Hi, new to the forum and looking for suggestions. Hopefully I can get more responses than the last chevy forum i posted on, 1 response would be more

Below is what I asked on other board....

Starting platform...
'99 Tahoe, 5.7L, running 285's w/3.42's, all stock except true dual tails from cats out the back.

Issue- I have a low oil pressure issue ( replaced sending unit, new oil pump, added mechanical gauge, still problem), I have bad lifter noise in winter when cold, now does it when warm outside too, and runs rough until it warms up, and finally, maybe the lifter issue, when under load, it begins to cut out, loses power, misses, and throws SES, mayne injector issue too. Last time I scanned, it was #4 cyl miss.
With the low oil pressure, I at least need to go through and replace bearings and check out what's going on along with lifter issue. Figured I would upgrade while I got it apart.

Goal- I need a good running daily driver with some low end umph for occasional trailer towing up to 4500-5K#s or so, but on pretty limited budget for rebuild. I rarely ever take this motor over 4K in rpm's, just not needed.

Rebuild ideas-
New bearings,- mains, rods, cam.
Inspect pistons, re-ring if not out of spec, bore and new pistons/rings if needed
Replace all gaskets
Replace spider with GM upgrade
Upgrade to slight larger cam
Maybe light port/polish of heads/intake
Aftermarket tune- maybe Black Bear or I know a local speed shop who maybe able to tune.

So, my main question is I guess, is cam recommendations. I see guys recommending Lunati, Howard, I've been a fan of Crane myself. I have no plans in future of any real mods other than maybe CIA, gears, and/or possible long tubes, but most likely nothing else. I believe a slight larger cam would help over stock, but I know it's limited without other upgrades/intake/fuel upgrade.

So, what kind of specs should I look for in a cam and maybe new springs also?
Any rebuilding ideas would be great.

Thanks

stock production LT4 cam
and
a tune, black bear could handle no problem

I had thought about the spider upgrade myself but I think that you can get more fuel out of the poppets that may be needed for the cam upgrade.

TJ

Mods, can you please move to the Performance section?

98Blackss wrote:

stock production LT4 cam
and
a tune, black bear could handle no problem

I had thought about the spider upgrade myself but I think that you can get more fuel out of the poppets that may be needed for the cam upgrade.

TJ

Thanks.
Do you have any idea of what LT4 cam to go with? I've found specs on at least five different stock LT4 cams, one being about the same as one in my motor now.
I already talk to Black Bear so I may go that route when I ever get there.
I think I need the spider upgrade anyway. This thing has ran rough since I got it at 99K, about time for replacement IMO.

Factory LTX Camshaft Specifications**:
1992 Y-body: 205/207 0.451/0.450 lift 117 LSA
1993-1995 Y-body, F-body: 202/207 0.450/0.460 lift 116 LSA
1994-1996 B-bodies (including L99 4.3L): 191/196 0.418/0.430 lift 111 LSA
1996 Y-body, 1996-1997 F-body: 200/207 0.447/0.459 lift 117 LSA
1996 Y-body, F-body LT4: 203/210 0.476/0.479 lift 115 LSA

Check out this other thread. It has been much discussed here on this forum. This is one of the latest threads. HOG may chime in. He is the walking encyclopedia of GM parts. I get the impression he works at a GM dealership. He knows his stuff though so that is why I chose this thread.
http://www.pacificp.com/forum/viewtopic.php?t=11200&sid=ce0072bfc508e54990292bb334f66700

Quote:

GM part number 12551142
LT4 production cam 1996 Grand Sport Vette, all 1996 manual 6 speed equipped Vettes, and the manula trans equipped 1996 Collectors Edition Corvette. It was also used in the 33 LT4 equipped 1997 LT4 Firehawks, and the 99 or 103 LT4 equipped 1997 LT4 SS Camaros. The LT4 engines have LS1 power in the last actual 4" bore 3.48" stroke Chevy 350 engines to ever be installed in a car.(The Vortec 350 continued on into 2003 in the fullsize vans and into 2012 in GM marine engines). I have seen LT4 dynos showing anywhere from 290-310 rwhp. A 1997 LT4 SS Camaro was tested by Motortrend and it nailed a 12.8@ 109 mph in the 1/4 mile IIRC. To avoid emission testing recertification for the LT4 Fbodies, SLP reused standard LT1 calibrations in the LT4 equipped Firehawks/Camaros, as such were neutered with the stock LT1 5800rpm rev limiter. The LT4 equipped Corvette (Y-bodies) were unleashed wit their stock LT4 calibrations and the requisite 6412 rpm rev limiter. The higher strung LT4 with its higher rpm propensity forced GM to use roller tip and pivot rocker arms to avoid the rockert arm and ball nut galling which occurs over 6200rpm with tconventional stock stamped steel/ball nut assemblies. The 1996 Vette/1997 LT4 F-bodies and the few hundred LT4 crate engines that were available were the only V8 vehicles/engines that GM has ever produced which use BOTH a roller tip AND roller fulcrum. The newer GM GEN III and GEN IV engines use roller fulcrum rocker only. For the 1996 Y-body(Corvette) there was 2 recalls related to the LT4 roller rockers. GM asked new Vette owners top not drive their cars asnd have the roller rockers retrofitted with a newer redesigned rocker arm assembly.
I have a keen interest in the LT4, as if you couldnt tell LOL.

Duration at .050" lift is 203º/210º, lift with 1.6 rocker is 476"/480". LSA 115º.

That is the cam I would install in my truck.

TJ

IMO, if you're going to re-bore, might as well buy a factory balanced stroker kit. $1,647.95 (forged)

http://www.summitracing.com/parts/SCA-1-91105BIE/ $1,259.95 (cast)


http://www.summitracing.com/parts/SCA-1-41755BIE/

IIRC, Grinding the crank is like $200, balancing is $200, new bearings $$, new rod bolts $$.

New bearing caps bolts/studs will be needed, freeze plugs, cam bearings...

RE-ring is a bitch because of the quality vortec METRIC rings. And you got the hone the cylinders for the new rings, kind of hard to do at home. And it won't be a great job cause 90% sure the cylinders will have wear, scratches, ridge...



So add to that new +.030 pistons $130
http://www.summitracing.com/parts/SLP-H423ACP30/

4bolt blocs from the shop can be had for 300-$400

And the time it takes.... + the $350 cam and $200 lifters and $200 springs and rockers and............



If you want plug and play, go crate. $4,655.00 Done.


http://www.crateenginedepot.com/HT383E-Performance-Crate-Engine-17800393-P10402C944.aspx

http://www.crateenginedepot.com/Chevy-Small-Block-Engines-C944.aspx