Ok guys i have a 96 excab silverado 4x4. I took out the stock 350 at 240000 miles and droped in the ht383e and after 2 years i have decided to get a diffrent engine because i cant aford gas at 13 mpg ( stock 350 got 22mpg all the time). The other thing is this engine seams to have less power then the old 350 did. I have not bean happy with the 383 from day 1.
My questions are should i just get a stock replacement and put a little bigger cam in it or should i try the ls1 swap??
Im going for no less than 18 mpg but i also like power for towing. But mpg is more inportant to me at this point.
How hard is the ls1 swap to do and what kind of mpg should i get if ur the guy that sais to go with the ls1?

If you are using 10% ethanol gas GOOD LUCK with getting 22mpg. That seems WAY too high on a stock L31. Is this with stock tires?
Look at the fuel mileage a LS engine gets in a truck...... 18mpg HWY maybe...... Not combined. The new motors
With variable cam timing get 19-21 hwy, not trying to be an idea buster but 18 mpg at BEST is probably all you will see with fuel now a days with the moonshine mixed in it.

What? You sure less power?

How many miles on the 383...got a price shipped? to 11703

Foreverfalcon40 yes it seames like less power my friends truck that is completly stock feals like it has more power than mine dose. I have k&n intake tb spacer 0411 pcm dyno tuned and no cats and flowmasters. The engine has probly 3000 on it its a little over 2 years old now and i havnt bean happy with it from day one.

Hmmm, what us your dyno numbers? I am extremely interested in taking this motor off your hands.

The whp is 208 and tq 400 the tq is nice for towing but sence i joined the army i dont tow as much. well what would u give me for it its 5,500 when i bought it from gm and where r u located and i would have to get a stock 350 brfor i can pull it this is my dd and the only vehicle i have down in ca

You know torque is what really counts.

$2,500

If you were closer I would give you my motor too. 130k on it with slighty built heads at 110k all new gaskets

There has to something wrong here, remeber reading 383 Maxing out the fuel system and the 60.

This is my only mode of transpertation and i dont have to money right now to get another engine right now. I can probly do it with my taxes.
As far as price i was thinking $3,500 so if u want to meat in the middle or somthing there?

If u pm me ur number then we can text my phones having problems using internet for some reason or i can pm u.

For what it's worth......
You can buy a COMPLETE running L31 with intake and all for $700 all Day long off of car-part.com and swap it in place of that 383 in a day easily. Heck it only Takes 2 hrs to remove a motor if that so you can Swap in a stock motor in a weekend and sell the 383 and Make a lil cash if you don't want it anymore.

$700? not in utah you cant. yards think they are made of gold or something

Well guys i dont like getting engines from a junkyard that im putting in my dd with out rebilding it first,most of the time nothing is known about the engine. im going to get one from gm mostlikly.


Stroker97k1500 i am going to sell it i just have to get a new l31 for it befor i sell it

Sorry I'm calling Bull$hit on 22 MPG ! You are telling me that you could go 500 miles on a tank of gas ??
As far as power goes, not many of us dyno stock trucks with stock engines, so finding a comparison might
not be easy. However there are many things that can influence the way a truck feels, but that doesn't necessarily
make it faster, have you ever raced your friend ?

-Justin

The 383's egine displacement is only 9% more than the l31
With a different cam (l31) and proper tuning+gearing. I don't see why you couldn't get similar fuel economy.
How much would you save in gas vs the swap cost?

Luvss wrote:

Well guys i dont like getting engines from a junkyard that im putting in my dd with out rebilding it first,most of the time nothing is known about the engine. im going to get one from gm mostlikly.


Stroker97k1500 i am going to sell it i just have to get a new l31 for it befor i sell it

I purchased 2 motors through car-part from 2 different yards and had great success actually. (each yard offers a warranty bw 30-90 days) The first motor I bought was a stock L31 from a 99 escalade complete with intake/distributor etc for with 180,000 miles on it and the damn thing ran like a dream(stronger and more quiet than most L31's I have come across). I drove it for well over a year and a half as a daily driver and then sold it for 750 I think. The other motor was for a toyota truck. same results, ran great.

I checked prices and you guys are right about the prices. They are up a whole lot compared to prices in Ga, and especially when I was in the market a few years back.
It sucks about the 383 you have, but I can understand completely. Good luck man
Robby

Co-worker with a 2003 5.3 tahoe got 19mpg very conservatively driven.
Max 55mph on hiway.

Justin the only i have not raced him i take my chevy luv with a 350 in it home because its not only fast as he!! It gets 20 mpg with probly 500000 miles on the engine never rebilt but sence 78 when my dad put it together for a dirtcar. But it finaly spun a crank bearing a month ago so the engine is getting bored 30 over no. My friends on or and im in ca for 2 more years in july ill race him. But im more conserned because i cant afored to drine my truck. P.s. 500000 might b a little high dont know axual

Crazyhoe when i put the 383 in i lost 150 miles to a tank ruffly i was getting 400-440 miles to 20 gal of gas now i cant get 300 miles to 21 gal of gas. So i think i would save quite a bit by going back to stock engine size.

For the most part on the with thease trucks most come with 3.56 gear in the diff witch causes the engine to strugle more going down the road mine and a couple others i know of have 3.73 gears and the engine dosnt have to try as hard to move the truck so it gets a little better milage thats y the trucks known for lower milage than it is capable of. Im not the only one with the " unbelivable " milage.

Luvss wrote:

Crazyhoe when i put the 383 in i lost 150 miles to a tank ruffly i was getting 400-440 miles to 20 gal of gas now i cant get 300 miles to 21 gal of gas. So i think i would save quite a bit by going back to stock engine size.

Outch!!?

If the 383 short block is good, and you still have the L31heads and cam, you would get similar performance but at a lower rpm band, IMO
Anyone?

Luvss wrote:

Hi everyone i am perty new to this forum.
I have a 96 4x4 extended short chevy with the ht383e in it.
My mods are 0411 pcm, k&n intake system, air aid 1" tb spacer.
I have had the truck dyno tuned.

My questions are what kind of hp and torqu should i get at the wheels? Mine only puts out 208 hp and 400 tq at the wheales. What kind of mpg should i be getting? I only get 12-13. From what i have heared and read people get 18 mpg.
Im thinking of putting the marine intake on it, will that be worth it or just a waist of $$$ and time?

Thanks for any help or advise

It's not the "383".
There's either a major flow restriction, or your tune is too rich, or your timing is too conservative, or all of the above.

I didn't check your cam, but with 400 tq, you should have around 350hp.
Only 208hp! That's were your fuel consomption is lost and it feels slower.