Ive got a 350 5.7 LO5 in my truck as of now. I have about a 3,000$ budget (i am working and as i work saving it up for the truck). I see all these posts on LO3s and mentioning the 200-250hp range, but could i get my LO5 to the 330-350+ range for about 3,000$? Would i get a big power gain on a new chip, aluminum vortec heads, LT1 cam, 4:11 gears, and new headers? What power am i looking at with these mods, and what other $ would i be looking to spend EXTRA after purchasing these mods?? Thanks guys!!

 

Geussing power out puts with these motors is really a stab in the dark. It all boils down to fuel delivery, TBI unit size and tuning when you get past 305 CI. Your parts selection is right on track. You will need hedders, new cam, heads, TBI unit, and pleny of tuning. You won't see more than a few hp without chip burning. I would try a few searches on vortec heads. They are the best bang for the buck when you are on a budjet. I would also look at a set of used L98 (350 TPI) heads. Both can be made to handfle large amounts of power for relatively cheap . For a 350 I would go bigger than an LT1 cam. However, you have to be carefull because going just a little bit bigger than the LT1 specs will require a little head work to accept the larger lift.

 

Hey man thanks for replying! I have a couple questions..How much tuning am i looking at and what needs to be tuned and how? What is chip burning? Is installing 4:11 gears hard, should i go with 3:73?

 

I'd go with the Iron vortecs personally over aluminums, because if I recall right the price is quite a bit higher for the aluminums, could be wrong though. But definitely go vortecs I think and a bigger cam than LT1, ZZ4 maybe?

Tuning, you MUST get into, read in the Tech Articles the intro to Prom Burning. You have to basically completely revamp your whole fuel and timing curves and a few other things. It won't run right at all without the chip tuning.

 

Theres no way you can make 350 HP at the wheels with an LT1 cam. Tell u the truth, 350 at the wheels is probably going to require at least a hot cam. Shifty was right about the L98 heads, but make sure they are the vette aluminum heads, not the ones out of F-bodies. They also have to be fully ported and machined to accept a larger cam.At the risk of getting the tbi people mad, you probably will need a different mode of induction.

Edit: of course 350 at the crank is much easier

 

I think he meant 350 at the crank. That is doaable with an Lt1 cam and some 1.6 RR's. It would be close though. The Iron L98 heads aren't that bad really. The aluminum ones are ideal but the iron ones can be real performers when ported.

 

If it was me, and I spend alot of time dreaming about a truck project some day, I would concentrate on torque not HP. I would go with iron vortec heads, vortec TBI manifold, and that GMPP 383 truck roller cam with 1.6 rockers. They use that combo in the ramjet 350 and get 400 ft lbs and 350 HP. Before anyone yells at me, I realize that they have a different induction system, but still this would be a stump pulling son of a gun. And it shouldn't be hard to tune.

 

Thanks guys, given this a lot of thought.. LO5s come stock with 300 torque at the rear wheels, could i get this figure to 400 with some of the mods you have given me? My truck comes stock with 210hp at the wheels and 210-350 is a 140hp gain, thats highly unlikely without going bigblock i guess...Could it be easy to go from 300 Torque-400+ torque? Maybe 420? Give me some torque mod ideas please guys!! More torque could help me more than hp from light-light correct?? IDEAS please!! Thanks!

 

I think your numbers are at the crank. LO5's may have made that at the crank but not at the wheels. That would be LT1/LS1 territory. However, even a simple heads and cam swap will put you close to your goal.

 

Thinking that i know not enough to choose these by myself, could you guys select a pair of heads and a cam and chip that i would need to complete this? How would i need to know the correct size heads i would need? I could just buy a chip and stick it in right? Not really mess with it a lot right? Thanks guys!

 

Well you are going to have to do more than just buya a chip. You will have to learn how to do it yourself or do what is called "data logging" and send the info to a burner to have it done for you. Mail order chips like that though are at best a stab in the dark. Every car needs something different than the next and the only way to get the chip right is to burn a whole bunch and keep making corrections till the data is right. Data loggind is using a lap top with some software that plugs into your ALDL diagnostics port that will store al kinds of info that the ECM is controling. It is to hard to just tell you what heads and cam to get but I would look at some worked over vortec heads, aluminum L98's, or ported iron L98's.

 

Yeah i understand what your saying, but cant i just buy a custom chip? I dont have a lap top, a desk top i do...An LT1 Cam(if its my best bet for a cam) wont throw a chip i can order for a loop, as someone said..I dont want to burn my own chip i just want to buy one. Where am i standing from here? What do i absolutely have to do?

 

Well you can buy one but it will only be a stab in the dark and not make as much power as you could. I would invest in a $30 laptp that you can get off of ebay. That you need the software which is free and a ALDL cable to go from the lap top to the port. Then you can save data and send it to a chip burner. There isn't any way to get a new chip that is right unless the person burning the chip has that data. It is like a blind man picking out his favorite picture. Talk to Brian at www.tbichips.com. He can get you started with a chip to get your car to run and then you can send him some data logs to help dial everything in. It really isn't as bad as it sounds.

 

Yeah but the only problem is i dont know what to send him(the logs or whatever) you might have to help me with that..Plus i havent set in stone whitch heads/cam i need! What would you do man, pick out a cam and the right size heads for me and ill be all set...

 

Look at the Trick Flow 23* aluminum heads. They're good heads that don't cost as much as AFR's, but flow VERY well. Call Crane up and tell what you have. Most likely they're going to offer you what used to be called their Compucam series. They're cams that are ground to be computer friendly. I think they have 4 levels in that series. And in order to make it all nice and install friendly, get an Edelbrock TBI intake.

I hope this helps.

 

If it were me I would go with a set of modified Scoggin dickey vortec heads. They have all the necessary work done to them to accept up to 550 lift or so all for about 600 bucks. I would then use a vortec carb intake and adapter plate or the GM vortec TBI intake (pricey). As for cam selection I would have to think about it more. If I am going to have it be a screamer I would make sure I have a 2" TBI unit with the proper injectors. Than assuming I burn my own chips would look at a cam in the range of 210 to 230 duration and roughly 500 to 525 lift. With an LSA of 112 or higher. You may want to look at the LT4 hot cam or ZZ4 cam. Vortec heads do not need a lot of lift to make them screamers. They can get away with a little more duration and still have awesome high end numbers. You can find these heads at www.sdpc2000.com. f your budget does not allow for that that i woul duse regular vortecs with a cam that has the specs similar to the LT4 cam.

 

Actually, if by high end numbers, u mean to 5500 RPM

 

By screamers I didn't mean rpm but instead the massive amounts of mid range power that can be achieved. I should have said power horse.

 

I understand what you're saying about the vortecs, but what about emissions and "minor modifications" that we keep hearing about? I have yet to hear a story of someone putting on vortec heads w/o some sort of modifications.

Maybe it's just me.

 

Thats because the vortecs are technically not smog legal, and have a different intake pattern than normal heads.
To use vortecs in cali, you have to plumb your egr to your headers.

However if you dont live in an area where emissions are of no concern, all you need is a vortec manifold, and no modifications are necessary.

 

Cali hit is on the head. The only modifications you would have to do is plum your EGR some how. Even that is not that bad. However, if you get rid of it you can just get rid of it in the chip. Other than needing a differernt intake the vortec head bolts on like any other small block head casting.

 

Im not too sure about emissions in Texas but thats where i am...am i in good shape? Worse than in cali? How much hp/torque gains should i be looking at with these mods? Im goin with the Scoggins/intake/headers/zz4 cam...........What else am i going to have to need with this setup? Whats a 2"tbi unit..do i need bigger injectors? Thanks much

 

Well i dont know about texas, but NOWHERE is worse than cali when it comes to the smog *****

 

Isn't that the truth. I don't even live there and from what i read I will never be able to move there because none of my cars would pass. They even have special gas over there. It is rediculous but necessary to say the least.

 

Here the highest gas they sell at the pump is 91 octane, which means you can only run ~10.5:1 compression ratio WITH aluminum heads (and about a point less with iron heads)

 

We have 93 here, but every city has atleast one that sells race gas which is like 103 I believe.

RoXsoX: Yes, you'll need bigger injectors. With that cam, I'm guessing maybe a 30 - 40 HP increase. You'll need atleast 65# injectors, but here's what I'm running and I'm going with 90#'ers.

350 / Trick Flow alum heads / 204-214 .429 .452 cam / Edelbrock 2" TBI intake / 2" TBI / Hooker 2055's w/ 3" cat back

I'm shooting for 350 HP, and I imagine with your bigger cam, but smaller heads that you would be in the same area.

 

There are two 2" TBI units out there and both require some sort of modification to get to work. There is the Holley 670 and the factory GM 454 TBI unit found on early 90's big blck TBI trucks.

 

Yeah i see the Edelbrock Performer Tbi manifold for 350$ in this magazine(i havent searched for cheapest price yet..) and the holley 670cfm with a 2" throttle bore......it says up to 25% more HP, is this correct? 25% more hp would be close to 53hp alone from just modifying my TBI??? If i did that +heads, cam, headers, chip i would be pushing close to 340hp! But +53hp from the upgraded TBI alone is too good to be true? For the REQs it says 88-89, i think mines a 90, so do i cancel this idea or will it work anyway?

 

Don't fall into the temptation to stack HP claims of manufactuers. You will only gain power on TBI systems by adding parts if you make the right changes in the chip. If not you are likely to lose power or a lot of drivability. You can get the Edelborck TBI intake for less than 250 from summit or jegs. However, it only has the stock 1 11/16" bores and would need to be bored to accept a 2" TBI unit properly. For anything over a 305 I would go with a carb intake with an adapter plate.

 

$3000
-2000 for decent thirdgen

$1000
-500 headers, full exhaust, and aftermarket intake manifold
-500 cam, 416 heads and springs, junkyard 3.42 or 3.73 rear

$0

save up for a posi unit ~ $250

faster and fun'er than a heavy ol' truck anyday

 

It has posi...How much would changing my rear to 3.73 or 4.11 make a difference? Whitch would be better? Any good gains? Troublesome to install?

 

Depends on your power band. Consult with the drivetrain guys for help. There not exactly a bolt on and require some skill. I would never trust myself setting the proper lash back there.