Ideas for a rebuild on 5.7

[usmceric1]

Hello all, I have a tired Vortec 5.7l in my 96 ext cab short box. It currently has 167k on it. I plan on keeping this truck for at least another 150k. I have a feeling I will have to rebuild the motor and tranny at some point. I am looking to upgrade power a little from the stock 250 to better compete with the more modern trucks. I think stock this motor came with 330ft lb...so an upgrade there would be good too. It is 4WD, with stock 3.73. Maybe going to a different gear for better high speed highway cruising, but retaining its load capability. I am looking to spend less than would it would cost for the GM performance HT383 motor and installation. Thanks in advance. Have a great Christmas!!!!

[ryiguy]

Well first off my truck has 275k on same motor and i haven't had to rebuild yet"its a 89 350tbi" I did have to replace the tranny at 218k. If you are going to rebuild anyways go with heads and cam. might as well if you have it apart. There not to bad on price and you will see a nice improvement.

[nnunez]

I would not only rebuild the top and leave the bottom untouched. That would be sort of like taking a bath and only washing your head and not your nuts.

Perhaps look into some trucks magazines to find a crated high(er) performance engine to replace yours.

If someone knows how replacing the rear axle on a 4wd will affect the truck, i am all ears.

[72'CaminoKid]

with it beign 4wd, if you're gonna replace the rear gears, you also need to do the front or the 4wd will be useless. also, RYIGUY, i'm not positive but i dont think ya'll have the same engine if his is vortec and yours is an 89, i dont think the vortec is that old but i'm not 100% positive....back to original post. why are you thinkin you need to rebuild soon? is it lacking in power or is there some other obivous reason, or is the high mileage just got you prepared to rebuild?

[usmceric1]

Well, I was thinking of nipping it in the bud before the motor finally goes. I bought the truck with 165k on it, so I don't know if it was abused or not. To me the truck runs fine. Starts up everytime, just a little clicking noise while at idle...sounds like its coming from the fan/radiator area. When its cold and I start it up I hear the starter engage...sounds like a hammer hitting the block. The heater makes weird noises and my a/c doesn't work, but the powerplant seems fine for now. This is y first GM product, and also my first truck. I think I have gotten it up to about 80mph on the highway, but it doesn't like it. I know trucks aren't meant for speed, but I should be able to cruise at around 80 I would think. The 4WD works great in 4HI, but I don't think it goes into 4LO, at least the button doesn't light up. I just put 285/65/16 BFG AT KO's on it. I was told that the SBC was easy to work on and cheap to fix if it broke...which it hasn't. I just figured that if I was to keep it for the long haul, and save my money vs. buying a new truck...that I would want to get the best I could out of it. It has some surface rust on the bottom of the doors and below them but nothing bad...I think its due to the shiny trim pieces that are there. The frame looks good albeit with some good surface rust ...esp on the rear under the bed (maybe it towed a boat). I just want to get some more power from it, so instead of doing things to a tired motor, that I would just rebuild with the power add ons then. One of the ting I would like to do is raie the bed up level with the cab. Seems saggy to me. Maybe beefier leaf springs would do the trick? Its an older truck but I love it...its a Chevy and it does what I ask it to do. My dad had an 78' K10 or K20 I think, and thats what I grew up with. I am not too fond of IFS, but I don't plan on doing much..if any off-roading, or plowing for that matter..(I never would with a 1/2 ton anyways). I would just like maybe 300-350hp and around 400ft lb. I think that would be nice. I don't care about loud exhausts..I think they are mostly for show.....I want more go. Thanks...sorry for ranting

[72'CaminoKid]

no its fine. the more info we have the better. let me pndoer for a while on what you could do to help and i'll post it back later. in the meantime i'm sure 75k350 will pop in with some good ideas, as well as john wayne and mudseeker. they tend to have lots of knowledge on exactly this

[436'd skylark]

I wouldn't mess with the heads. very decent flowing heads from the factory. probably a good valve job and some beehive springs. a bit more cam, open the exhaust up, and some computer work, you'll be happy. I'd leave the 3.73s, but 4.11s are always nice.

[75K30]

Reading your post tells me that the engine seems to be alright, but you have some issues with other things not related to the engine at all.
Bad heater, no A/C, and a knock when starting, all sound like issues that will still be there even if you change the engine.
I am always up for more power, as is anyone. Your goals are easily obtainable, but will cost some money, and I believe that this small increase in HP and torque is not justifiable when the current engine is still good.
These mid 90's 5.7's were strong engines, but used ver conservative cam profiles, and really woke up with a cam upgrade.
I believe you have an already capable powerplant, it just needs a little help getting things excited.
Joe had a decent idea with regards to the exhaust. Yours especially has a very restrictive set of maifolds, and that crossover necks down ver small. Some of the internal bends reduce to less than 2 inches. Way too small for decent power.
Gear changes are always a great idea, but I would not be too quick to jump into this, just yet. You are running a rather short tire. At only 30.6 inches tall, the 3.73's will be alright. While I kinda prefer a 4.10 with that combo, I am afraid that it would be too much cost with not enough return to justify this.
Decent cam, and a good tune will be the most cost effective solution.
Leakdown and compression checks to verify that the block is still healthy should save you some money.

[mudseeker]

anything you do to upgrade power is going to come at a decent price. while the crossover is unusually small for the engine, to replace it will cost over $100 due to the convertor being part of the unit. if you know someone with fab skills, you could make your own crossover and keep the old convertor or opt for a new high flow unit.

like the others, i would invest in a cam if you're unhappy with your engines performance, but i would save your money for the tranny rebuild that will be coming soon, if the truck was used for towing by the previous owner.

my truck has 196k on it and aside from the oil leaks, i have not had any trouble from the engine. the same cannot be said for the rest of the truck though. lol

[usmceric1]

Yes the truck runs good. So a more aggresive cam, headers, and a less restrictive exhaust. Maybe an exhaust with mandrel bends? What diameter? 2.5"? Shorty or long tube headers?? I have heard differnt things on this forum concerning headers. What about going true dual, instead of the single exhaust. I still want to pass emissions. I understand about clicking noises and things...its an old truck and I will fix these things on my own in time. I couldn't care less about air conditioning. Would taking the a/c out help with anything? What about the trans... I am pretty sure its the 460LE. Would I need to beef it up or rebuild it if I will be running a max of 350hp?? How much does a gear change cost? I know that there is alot to it, and I would be better off with a professional mechanic for that change. I don't plan on putting any kind of lift on my truck....its bad enough on gas. Like I said before, beefier leaf springs for more load cap..and a level look. Also....what about the brakes? From reading posts on this forum and driving my truck, I know the brakes are a weak point on these trucks....Do I just need a better pad or what? Thanks for all your knowledgeable answers.