I would like to hit 400hp at the crank but I'd like to do it in the absolute cheapest way possible ($1500 or less). Would it be cheaper do to it with a 5.3L or a Ls1? I've heard you can bore the 5.3L out to 5.7l but would that be cheaper in the end? Could I just make it with 5.3L without boring? Will 243's fit on a L33?

 

I'd like to hit 400 w.o. spray and I want quite a flat curve. Nothing close to peaky.

 

Youre either going to get close to spending that or over easy. Ill give you a rough break down on my build.

LS6 intake - 310
TSP Torquer v2 combo - 600
O2 extensions - 40 (x2)
O2's - 140
LT's - 200
ORY - 130
Lifters - 140
Gasket kit - 175 (got a steal....i mean deal.)

and to support that on a M6

LS6 Clutch kit and extras - 700 (master, slave, and arp bolts)

All adds up to - 2435.

Thats give or take. That is not including the oil and antifreeze. Other misc. stuff that I did replace during the build like lifter trays, ls2 chain, new cam gear and lastly the tune.

Should clear 400hp to the wheels.

 

Cheaper to cam the car with bolt on's - you will def hit 400 to the crank that WAY and cheaper than a vortec.

 

I do have a ls6 intake but I don't have any engine yet. So would it be cheaper to get 400hp at the crank with a ls1 or 5.3L.

 

well given the bore and displacement is bigger on the LS1, it would be alot easier on a 5.7 it is like comparing an LS2 and a LS3, of coarse it is easier to hit a higher number with more torque with the bigger bore motor, just matters what the budget is and what motor you have readily available to you

 

LS1 all the way!

 

Why buy a clutch that's only good for 400 - 425hp? You can get an LS7 for the same price and it's good for 500hp. Or get the stage 1 clutch from Diamond which is an upgraded LS7 for even less $ by using your stock flywheel.

 

Just a cam only ls1 with LTs and a tune should hit 400 crank
Most cam only ls1s with supporting mods are close to 400rwhp anyway
So say
700 on cam kit
250 on mail in tune
250 on used 42lb injectors
And 200 left for misc

 

with cam only the stock LS1 injectors should be fine (as long as they are 28lb instead of the 26.5lb ones). they will be runnin pretty high in the duty cycle, but i have seen plenty of people make 420+rwhp with stock injectors.

 

At first I needed a clutch first and wasn't going to do anything else. Got a deal on headers, then ls6 intake. I already bought the clutch at that time. I have been thinking about selling the ls6 and getting a ls7. But screw it. Ill run the ls6 for now.

If it goes, it goes. I do not go out to the track or even race much on the street. I will get on it, but that is how far as it goes.

 

Since you dont have an engine yet i would go with a LM7 iron block 5.3L which can be had from $150-450 all day long and they are everywhere. A LS1 is cost you a good $800-$1200 used depending on mileage. Assuming you would totally rebuild both look at the upfront cost on the engine alone. Bore the 5.3L to 3.898 (LS1 Std bore) and you have a 5.7L. You will only be able to hone a 5.7l LS1 alum engine so if you get one that has some deep scratches or wear then you just bought a ls1 that wont be usable.

The 5.3L truck motors came with 243/799 (same thing) heads starting around 2005/6. Keep an eye out at the salvage yard for those engines! Depending on what you are putting the engine in....your accessories may or may not work. There are 3 or 4 different accessory brackets that are used. The truck setup sticks everything out toward the radiator. The corvette brackets are tucked in towards the engine the closest. Then there is the F-body which is in the middle. The stock crank on a truck engine will need to be changed to a car crank because the snout and counterweights are different. You can get a rebuilt corvette crank for around $190 at any auto parts store. Stick a LS6 intake atop it, install a 02 Corvette cam in it, get a tune and you will easily get 400+rwhp. Don't reuse lifters, pushrods, gaskets or oil pump!
Either way you will be at the $1500 mark or over when its all done and running. I am rebuilding a LM7 to LS1 spec and sticking it in a 85 Corvette. I picked up (2) LM7's for $250 each at a salvage yard in Oklahoma.
Try car-parts.com for your search for engines. Try 2002 Chevy 1500 engine assembly click on the LM7 5.3L when it shows you engine sizes. The ones listed as burns typically are real cheap. You just gotta decide which computer you want to go with and whether or not you want to have to buy 799/243 heads.

 

I'm guessing a thrown rod bearing would be a good target and risk getting a set of heads that are hurt? I'm also guessing I should just buy a used ls1 assembly and throw it in. Then I don't have to balance the crank and everything.

remauto1187: that's exactly the answer I was looking for, thank you.

 

Ive heard of people getting used ls1 pistons and building an iron block. But me i figure its a crap shoot at whether you get something that is not usable or worse yet you end up finding out it wasnt usable AFTER you put the engine all together and it comes apart on you. I want a reliable, stout engine that will give me many years of no trouble. I dont like paying for stuff twice and i certainly dont like paying for stuff twice. If you need any part numbers, sources or have any questions feel free to post here or PM me. If i cant find you the answer someone will chime in here. Its just a matter of time before the LS1 queens start chiming in about how you MUST start with a LS1 block because its "cheaper" or the "big boys" that insist on starting out with a 6.0L. Which is fine if the car is going to be a track queen racing for money and you have the budget to build the sixxer.

New set of pistons (STD) with coated skirts can be had for $320 right now on fleabay! You can reuse the original truck rods...they are the same part number as the car ones! (5.3l vs 5.7l)

Trust me if you have to save up another couple months to get everything done right, do it! It will be worth the time and money spent. Dont rush it. I absolutely refuse to rush my build. I plan to have my pistons this month and then off to the machine shop the block and rotating assembly goes.

 

I've actually been looking through the performancetrucks.com forum. It seems these guys are pulling 400hp quite decently keeping the blocks at 5.3L. Not only that but they seem to be getting better mpg than a ls1 build. I know my build can never exceed 500hp due to the tranny on the porsche 944 I want to throw this into. The next step up for a tranny is 5 grand so that won't be happening soon. I understand not to rush things because I made a big mistake of jumping into things last year and I spent a good chunk of money on parts that I did not need.

 

Yes as light as the 944 is a 5.3L built should do great in it. I had a 1978 924 some years ago...with an automatic! The transmissions and rearends arent very strong in the 924/944. You might want to atleast upgrade to the 944 turbo rearend/tranny if they are different than yours. The stock 4 cyl. was not exactly a power house. But i know that since the mid 80's people have been putting 350's in 924/944's so there must be some kind of magic parts combos. Try a search for porchev ....that was the moniker that was used back when all the adapter companies made adapters to install a sbc in a porsche.

 

The 5.3 that came with 243/799's are code L33. They were in 05/06 ECSB/CCSB 4x4's and Z71's. They were in about 1/3 of those trucks.

 

That is incorrect year and model data. There is a Government truck at my office that we have had since last year and it is a 2010 chevy silverado 2WD 5.3L with 799 heads on it. You can find the 799/243 heads on ANY GM truck platform from 2005/6 and newer 5.3L's.

My bosses 2007 or 8 avalanche has 799 heads on its 5.3L too.

 

I was only referring to L33 motors since the original poster asked if they would fit the L33.

 

ahh roger that!

Better get em while the gettin is good! I have (2) 5.3L's in my garage right now. One is all tore down and going in a vette. The other is going into my Sierra probably next year. I am thinking of grabbing atleast one if not two more and just squirrel away in my garage.