Hello all, I'm just starting up a thread, I am in the process of pulling a 5.3 from a '02 Silverado. Motor is going into an 88 GTA. Car is built, Koni Yellows, Eibach Pro kit springs, tubular suspension compoenents, working on a LS1 brake swap as well. T56, 3.70 9 bolt (have a 3.73 10 bolt on the bench), 350 TPI with an LT1 cam.

Now, this is a street car with emphasis on handling and maybe the occasional track duty. I've set the target at 500 horses (AT THE CRANK), more would be gravy, less would still be a bloody fast street car. Everywhere I look, people say it can't be done without forced induction. However, here is the flaw with that, I'm after 500 at the crank, not at the wheels. Due to that, I'd rather stick with a winding NA motor. Here is what I'm looking at doing...

LS6 intake, LS1 or LS6 rails, I've heard '13 GT500 injectors will work, but I could be wrong, I have the 78 I believe mm TB from the truck, but would likely need to go bigger. 243 or 317 heads, looking at the flow charts, no reason I couldn't port and install bigger valves on the 706/853 truck heads, could wind up close to if not the same numbers as the former. Texas Speed cam to be determined. Either leave the stock bottom end alone or have it bored out to run LS1 pistons. Full exhaust and a good tune.

This seems to be a generic proven recipe for 500 crank horses give or take. Any input? I already know I'll have to modify the fuel lines, and wiring, and upgrade the pump in the tank.

Thanks! May have to post often to be able to use the classifieds for buying...

 

500 at the crank with the 5.3 is going to be a challenge. Cheaper and easier to do a mild cammed 6.0 short with L92/LS3 top end. Common parts, well proven combo, under $2500

The machine work on the block and heads to make the 5.3 breathe are going to eat into your budget before you buy any more parts

Dont forget the expensive SSW headers when swapping into a 3rd gen, nor the other expensive parts like Fbody accessories, oil pan, wiring, trans/axle to handle the power etc

 

I would sell the 5.3, pick up a 6.0 short block and add a decent cam and LS3 top end. That will easily do it. The 5.3 will be an up hill battle without FI.

 

its your car and I will always advise do what makes YOU happy with your ride. with that said, my .02 is I have dealt with some nice 5.3's that put down some great power na, but 500chp out of a 5.3 will be a trade off. likely too much $$$, too much compression, and race fuel only. where a na 6.0 would be a friendly dd on pump gas and can easily achieve 500chp.

I have seen a na 5.3 with 500chp, but it was 13.5:1 compression, forged internals, flat tops, cnc'd 243's, ls6 intake with 90mm tb, big injectors, so on so on... very specialized parts that would have been better suited on a 6.0 or larger. required race gas, no pump gas.

I have a 1990 iroc g92 1le car that I am still collecting parts for. similar build other than I am have already collected a ls3 and a 4l80e. car is a driver, still looking for all the little parts before I tear the car apart.

again, its your car do what you want with it, no matter what any of us say here. happy motoring.

 

Well, we made progress on pulling the 5.3, believe only the converter bolts are holding it in. I should make a note to grab the OBDII diagnostic plug as well. Is there anything else I should grab other than everything under the hood?

As for the 5.3 vs 6.0 debate, it seems it will never end. I was looking for a 6.0, but couldn't find one that didn't cost an arm and a leg. The idea I had behind the 5.3 was it was only a bore job away block wise from an LS1. Obvious metal differences aside.

Iron "LS1"s seem to be an ideal route for a budget build (as in not a 12,000 dollar motor) from what I'm told and reading. I have the wiring on hand here. So honestly, if a aluminum motor of the same origin, can make 385-405 horses in LS6 guise, no reason why an iron version can't do the same. I rode in a CETA with over 350 at the crank, that was to this day one of the fastest cars I've ever ridden in, bested only by a '01 ZO6 vette that I drove. 500 is the target, but if I fall short and wind up with 450, I will more than likely be happy with it. These motors are already at close to 300, a good cam and tune will wake it up a bit. The car is a street car, but its not a daily driver. I have a car for daily duties.

The car the motor is going into, is already a mid 14 car on paper, realistically 400chp gets me into 11s if I can hook it (never happening). The qualm I have with the FI idea, is the engineering and build it yourself fab work that I'm not really able to do with what I have in the garage. Otherwise, I'd go T76 and say where do I sign? But as a street car, where can I really use 620 FWHP? I'd rather go N/A and save myself the fab headaches involved. Besides, I am seeing builds that run on pump gas that get into the 400 CHP range. Particularly if using the parts in my first post and a cam and LS1 pistons are involved.

The heads btw are your run of the mill "706" heads, should I have them worked over, or go with 243/799s? As for all the "extra" parts, I went into this already knowing I will have to make changes to the oil pan and the like to make it work. So I'm not worried about that. Final question, are the pin outs on the '01 and '02 PCMs from the Silverados the same? Reading around it seems to be so.