wouldn't have found it w/out Pauly's link on one of my older posts.

So thanks Pauly

RStahoe99 wrote:

I found this write up at hotrodlane.com, for an 88 but good info and part numbers.

http://www.hotrodlane.cc/Streetstories/81%20swap.pdf

Yeah, I had read through that...That is for an 88 1 ton...different body style...But he does have some good info.

It is printed off in my file of 8.1 swap stuff

blackpearl wrote:

RStahoe99 wrote:

I found this write up at hotrodlane.com, for an 88 but good info and part numbers.

http://www.hotrodlane.cc/Streetstories/81%20swap.pdf

Yeah, I had read through that...That is for an 88 1 ton...different body style...But he does have some good info.

It is printed off in my file of 8.1 swap stuff

That is the same body style as mine, it definitely would be a different body for the GMT800 crowd and up though

HA!!!!

Thats the very same article where the fool hacks apart the frame....

All of the cutting to the frame is NOT REQUIRED, POINTLESS and a foolish waste of time. I wish I could talk to the guy from Wyotech that did the install and tell him to update his site saying he did it completely wrong.... and guys posting "Oh its got good info" piss me off cause it's NOT! its misleading and ass backwards, it shows how no research leads to alot of pointless fabricating "Lets just box the whole frame just to swap a big block. Man it pisses me off everytime I read it.

This post has the best info on 8.1L swaps. Everything else is guesses from uneducated guys....I have the engines in my garage and a running parts listed....Bet your a$$ I'll be doing a REAL write up.

Oh and to clarify others issue apparently Dynomax has 454 headers that clear on the 67-72 2wd body style on which the frame rails I am pretty sure are the same cause the 2wd suspension just bolts up with about 8 bolts or you can just bolt up leaf springs and make it 4wd and apparently even a stock chevy starter from a small block will bolt up and from what I have read the flexplate will bolt right up to a TH400 torque converter although I am running a 4l80e and a 203/205 Doubler. Which I will need to drill and tap the front of the 203 case to achieve according to the ORD website.

Sorry to thread jack just trying to continue proper information......

Nytmarek5 wrote:

HA!!!!

Thats the very same article where the fool hacks apart the frame....

All of the cutting to the frame is NOT REQUIRED, POINTLESS and a foolish waste of time. I wish I could talk to the guy from Wyotech that did the install and tell him to update his site saying he did it completely wrong.... and guys posting "Oh its got good info" piss me off cause it's NOT! its misleading and ass backwards, it shows how no research leads to alot of pointless fabricating "Lets just box the whole frame just to swap a big block. Man it pisses me off everytime I read it.

This post has the best info on 8.1L swaps. Everything else is guesses from uneducated guys....I have the engines in my garage and a running parts listed....Bet your a$$ I'll be doing a REAL write up.

Oh and to clarify others issue apparently Dynomax has 454 headers that clear on the 67-72 2wd body style on which the frame rails I am pretty sure are the same cause the 2wd suspension just bolts up with about 8 bolts or you can just bolt up leaf springs and make it 4wd and apparently even a stock chevy starter from a small block will bolt up and from what I have read the flexplate will bolt right up to a TH400 torque converter although I am running a 4l80e and a 203/205 Doubler. Which I will need to drill and tap the front of the 203 case to achieve according to the ORD website.

Sorry to thread jack just trying to continue proper information......

No problem man...at all. This thread is intended for proper information. This is the ONLY thread I've been able to find that has any info for swapping in an 8.1L into an GMT400 truck...I am going to end up doing this, but I have a feeling it's going to be done in a 2wd now as I found one for pretty cheap. I have another lead on a 94 4x4 that I'd like to do the Solid Axle swap to, so we'll see which one pans out.

Either way, no problem at all. I read that article because there was info in there regarding electronics and stuff...There is still good info in the article, it's just the fab work that may be off...Again, I won't know that for sure until someone actually gets this done...As far as I know there is ME, and possibly YOU who actually are seriously considering doing this...So until one of us gets after it, it's tough to say what will/won't work.

Nytmarek5 wrote:

HA!!!!
...and guys posting "Oh its got good info" piss me off cause it's NOT! ..

Some one needs to take a chill pill. It was not posted as a "this is how to make it work and the only way, if you don't you will fail" write up! It is what it is, someone's write up on how they did their install. Just because you would do it differently doesn't mean you should knock someone else's work.

This whole site is dedicated to helping each other out with the knowledge and info. we have. If the wyotech article helped in ANY WAY then it served it's purpose. I only posted it TO HELP! Personally I don't care if it pisses you off, it wasn't for you anyway. I don't appreciate the attack and if that's the attitude your going to take with someone trying to help out then do us all a favor and just don't post anything.

in the article, it states very clearly his intentions, he was going to box the frame anyway, not because of the motor swap, and looking at how he did it and WHY - i think he did a good job.

would i do it differently, sure would - but im not gonna burn him on how he did it - plus, if you are going to hack the frame, the way he repaired the strength that was lost is the RIGHT way to do it.

looking at the photos, it was a custom build - hell, with the lift and everything else, i would have boxed the frame with even a small block in there, im sure it will see the shows as well as some play time.

what he managed to do was put an 8.1 in there without any custom parts, he can get replacements at any auto store, and there is a lot of useful information in the article.

i know not everybody will hack up the frame to do what he did, but it doesnt make it wrong - at all.

could it be done without the hacking, sure - but then your looking at spending the money on the parts to do it and will be more expensive than what he did - different strokes for different folks.

but attacking a member for making a comment (positive or negative) is just wrong and not what we are about here, i understand the viewpoint, but i think some people need to learn a little bit of tact.

i know i learned something from that article, and thats always a good thing, regardless of how it was done - but i guess my glass is usually half full.

Well to answer your post of it "helping" most of the people that read it see that you "have to" cut the frame because that is what's written. and it steers people away from using the engine.... It doesn't list options like using FACTORY kodiak brackets, And mass produced headers that clear without mod to the frame... nothing custom... It's misleading and as far as expense the brackets are fairly cheap from chevy, you can sell the old ones on eBay and make close to all the money back and alot of the "complete" engines don't come with brackets so you'd have to buy them anyway. And I think the article does more harm, then good and I am passinate about bashing it is because in all my research and I have done EXTENSIVE research on this topic. 90% of the info references this article and says you "need to hack the frame" and on those articles loads of people say "oh then it's not worth it" and go buy 6.0ls or 5.3ls. If you look into it you'll see what I'm talking about on top of this it comes from a wyotech instructor so it's immediately taken as truth. More then say someone like
me who has done the research but isn't an "instructor" and am classified and "not knowing what I'm talking about cause I'm not and instructor" look around do your own research this article turns more people away from the swap then anything else.

I in no way mean to offend the poster of the link simply the source of the misinformation. Also I never said he boxed the frame just for the swap but let's consider the average guy doing this swap isn't going to box his frame (I'm not, cause I don't have the time or tools) so therefore it would make the swap a Herculean task when it's not. And without the frame boxed you wouldn't be able to do the bracing properly. It is don't correctly but
based on the fact the swap IMO is done wrong it doesn't matter... It's like welding blocks to a front axle it the smartest way to do something stupid.

As far as you guys working on the GMT400 body style trucks, look into sky manufacturing they offer a cheap SAS kit that could be modified for a 2wd and that may be your best and most cost effective bet and they will sell it piece by piece so you dot have to buy a whole kit just for a few brackets , cause you could buy a passenger drop case and run a factory gm60 and then just swap the tail housing/shaft or upgrade to a 4x4 trans.... For a one ton GMT that's the way I'd personally go.... I had one and that was my plan but like the blazer better so I ditched the project.

I'm not hear to bash any members on here. I'm just tired of seeing the same information pop up over and over this link was even referenced a few pages ago when I went on my first rant about it....

Also someone said it would be cheaper to do the work he did? Think about the time it took, include test fitting, now think about the expense of custom A/C tubes and the effort behind that. In the long run i'd bet my truck on the fact if you factor in the costs and consider time as money Including research what fittings you need, what angle fittings to get and that whole hassle when if you use te factory brackets. Guess what you can use.... You got it.... Factory lines (and throwing your custom back at you what happens over time when those a/c lines need to w refabbed/replaced?) it would be more expensive. There's more custom work an cost in what he's doing then anything I mentioned. Just my opinion take it or leave it I don't care my truck's getting built the right and proffessional way. So it looks factory.

Nytmarek...just curious do you really live in California, make a ton of money, have tons of women that can't get enough of you, and previously gone by the nickname Stealth97?

if not, my bad, you just remind me of him

Hahaha well every woman alive does want me and I make a ton of
money (not really) but no that's not a sn I've ever gone by and no I'm not from California.... Hope that isn't secretly saying I sound like an asshole lol.

Oh and blackpearl, just a friendly correction I'm not "planning" this. I am "doing" the swap. I've got two 8.1ls in my garage, the 4l80e is in the back of my zr2 and I will hopefully be picking up the doubler in a few weeks... As I said I'll have a write up, it is a different body style, but the way I think about it is: you have the same tolerence roughly cause both your truck and mine have the option of 454's and the 8.1l just isn't all that physically larger then the 454. I hope to drop the motor in and have the drive train mounted up within a couple weeks depends on how things go. I need to find a torque converter and clean and paint everything..... I want it to be done right so I'm taking my time and making sure I have all the parts ready to go or ready to be ordered before I just throw it all in.

Also like I said I'd almost sway you towards a 2wd base cause the truck will be cheaper but with the sky kit to make it 4x4 you'd need driveshafts, a tcase and whatever axles you are using if you can get all that cheap you may be able to build the SAS truck cheaper then buying a 4wd and swapping it all over. Also with the sky manufacturing kit I think it requires a minimum of 6 inches of lift. If you need any help I've been messing with Chevys for 12 years and this build has been on the back burner in planning since 01 when I first saw the 8.1l trucks.

It sounds cool. I can't wait for the pics.

Nytmarek5 wrote:

Hope that isn't secretly saying I sound like an asshole lol.

Well, let's put it this way... the fellow to whom he refers is one of two people I've ever seen banned from here, and I'm not sure if Johnee was banned or just quit coming back. He also had a Supra fetish. Saying something like Supras suck would have him slamming hundred of posts with screaming, slap-fisted anger. Naw, you just seem to have a real Supra-ish issue with Wyotech people, almost as if the person who wrote the article you keep slamming failed you out of the school or something...

It's a pet peeve cause everytime someone lists actual intelligent information, someone comes along and posts that link an says "look this is what you need to do" not "this is one way to do it and the guy did it wrong/ the hard way" believe me as I said this has been in planning for several years so you can only imagine how many times I've seen this, it's literally on any and every forumn that's ever been posted for an 8.1l swap it's infectious like a disease lol. look around for yourself it's ridiculous and as i've been saying guys have literally dropped the idea of the swap all together cause guys reference that particular link..

Even though from everything I've read the only downfall to the 8.1l is performance parts and weight but my rig stock is about 5k there's no point in trying to make it weigh as much as a wrangler (I'd just buy a wrangler) although how much power do you really need? And for the power hungry guys they make turbos and superchargers and from everything I've read it's a pretty solid consensus that the motors breath well and hold up fine to some serious abuse. hence thier use in boats and fleet vehicles. The difference in fuel milage is minimal from a 6.0l but the power is what only a big block can give you.... Guys claim cam and a tune on a 6.0 will wake it up bit it will also drive your efficiency and reliability down. With an 8.1l you are looking at solid 100,000 mile performance. This is why there are two in my garage. But half my ranting is done with a bug eyed smile on my face.

Any photos you can get of the passenger side rear upper a-arm frame mount vs. the exhaust manifold to post here would be welcomed and appreciated. The passenger side is the only problem-area with the whole thing. Incidentally, the 454SS pickup had a passenger side exhaust manifold with a relief cast into it to clear that frame component. While it's true that same manifold might work on a tall-deck with or without raised-port heads, I think a stock 2500/3500 Vortec exhaust manifold could clear with some trimming to the top of the a-arm mount just I had had to do to the Tahoe with standard-deck and standard port BBC. The bottom flange of the exhaust manifold (still talking about passenger side here) come close to the frame... VERY close. It is already just barely possible to get a 3-bolt flange onto the studs past the frame. I would have to suggest removing the studs (PITA BTW) from the exhaust manifold and running grade-8 bolts in them instead. The downpipe is going to have to take a sharp angle off the flange to clear the frame. I would presume that those measures would provide the needed clearance WITHOUT cutting into the frame.

The best way to remove the studs from manifolds is to use two nuts jammed tight against each other and then turn the entire thing. Liberal use of PB-Blaster on the thread going into the manifold, keep the threads under the nuts completely dry otherwise they'll slip.

Nytmarek5 wrote:

Even though from everything I've read the only downfall to the 8.1l is performance parts and weight but my rig stock is about 5k there's no point in trying to make it weigh as much as a wrangler (I'd just buy a wrangler) although how much power do you really need? And for the power hungry guys they make turbos and superchargers and from everything I've read it's a pretty solid consensus that the motors breath well and hold up fine to some serious abuse. hence thier use in boats and fleet vehicles. The difference in fuel milage is minimal from a 6.0l but the power is what only a big block can give you.... Guys claim cam and a tune on a 6.0 will wake it up bit it will also drive your efficiency and reliability down. With an 8.1l you are looking at solid 100,000 mile performance. This is why there are two in my garage. But half my ranting is done with a bug eyed smile on my face.

The HP3 Vortec 8100 525hp 560 lb/ft engine required a dedicated HP3 intake manifold to bearth at the 500+hp level N/A. It also required a specific HP3 cam that was done by Crane IIRC. The heads also required porting, there was a U.S. company that was contracted by GMPP to develop a CNC head porting program and the they requisitioned 60+ sets of heads.
You can get 390hp and 420hp(the 2 power levels) easily from the 8.1, but to make the jump to 525 hp requires, headwork, cams and intakes, all of which were specific to the HP3 Vortec 8100.
The HP3 makes 525+hp through a 75mm t-body, which is tehsame size as the 96-02 Vortec 305/350's use.

I personally dont think aftermarket PCM and camshaft tuning really hurt durability when done properly. 100,000 mile performance is easily obtained today, when compared to days past.

If I had a GEN VII 8.1(496) or a GEN V1 8.2(502) to choose from, I think I would have to chose the 502. I of the reasons that 8.1's are attractive is that they can be had in great quanities accompanied by a full PCM and wiring harness/fuel injection system. the only way to do this with the 502 is to buy a Ramjet 502, and even then your using the antiquated MEFI controllers. If I had a 502 longblock in front of me, I would grab the L21 24x reluctor wheel, Vortec distributer(for CMP signal) and run an L21 calibration(or similar).
The 8.1 will be a nice swap, I havent ruled it out myself, thats for sure.

peace
Hog

Is that from the Offroad unlimited baja suburban build? The info looks very familiar that's why I ask. As far as I've seen Raylar? I have heard is the only one to do anything for aftermaret heads. My main point with the "cam and tune" is all the 6.0 guys claim better fuel efficiency factory mpg goes out the window when you start changing fuel mapping and cam and ignition timing... And it's very dependent on driving style. Although I will throw it out there that with a tune you can make an engine more efficient but generally not if you are shooting towards peak performance... The whole reason performance lacks from the factory is because they are shooting for the best balance between power, efficiency and reliability (in theory).

The one thing that does suck about finding them with a complete harness and ECM is that generally you have to send the ECM put to get flashed anyway to get rid of the VATS system and the torque management thats programmed in them.

Also to the guy asking about clearence of the headers, I'm going after long tubes cause generally the primary tubes will carry the collector farther down the line so you generally don't run into as many clearence issues. Or you can alsways buy a build it yourself header kit. Which although my whole flow is the less custom stuff the better headers weren't that hard my landlord and I built some with custom made baffles for his supercharged 454 powered hot rod coupe (man that car is nasty)

One option I'm going to personally investigate also is the kodiak stock manifolds because on these trucks they made different accessory drive brackets specifically for frame clearence. they also use the older style starters, so I'm thinking the frame on them is a little bit closer to what we are working on so I'm gonna try and pop the hood on one and maybe I can snap a few pics.

Nytmarek5 wrote:

One option I'm going to personally investigate also is the kodiak stock manifolds because on these trucks they made different accessory drive brackets specifically for frame clearence. they also use the older style starters, so I'm thinking the frame on them is a little bit closer to what we are working on so I'm gonna try and pop the hood on one and maybe I can snap a few pics.

Keep me posted on your build man. I've been thinking about a 2wd truck, but I'm wondering if their frames are any weaker...Shouldn't be, but who knows. Either way, you have posted some good info, but the guys are right, you do come off VERY defensive No problem though...FWIW, I am "DOING" this swap too, I am just in the "planning" stage