i've pretty much decided life is too short to leave my 99 coupe stock since i'll never sell it so i'll never worry about the monetary benefits of leaving it stock. but i'm also shooting for around 600hp and i don't want to push the ls1 that far. so here's my question: should i mod the ls1 or get the c5r and build it up over time then drop it in the car once complete? i don't have the money for it now but i don't want to buy parts for the ls1 if i'm gonna get the c5r. and also does the c5r only come as the block or can i get a crate engine typesetup for it somewhere?

 

You have to be a fanatic to buy a C5R -- and seriously, have a lot of $$. Mine cost $55K by the time it was sorted out and adding 355 RWHP. There are several less expensive and perfectly satsifactory routes.

LS7 crate engine. Not sure what they run for now. $10K? 450 RWHP stock. With mods they can go to 525 cheap, and max of 600 at the wheels, barely, and be durable (be nice to it).

LS7 or C5R block (there really isn't much to choose between them, buy whichever you find cheapest) with aftermarket rotating parts added, and a good careful build.$18 -$40K in addition to whatever the block costs, depending on how much you want the really premium nut-case best, and who you have build the engine. Up to 1100 RWHP with SCr and NOS(another $25 K max), etc., if you are crazy enough and have enough $$.

402/414 aluminum block stroker depending on whether you use a LS6 or LS2 block. About $8k done well for the basic engine, $10K if you go with premium valve gear, etc. (not worth it). Can go to 600 RWHP with either light boost or NOS or heads and radical cam. But go too far and you blow it apart, but otherwise it will do you well.

Cast iron short or long block 408/420. Cost about $8k for the basic motor, $10K if you buy premium Jesel valve gear, etc., which you will regret not having when you push the RPM limit up.. About 475 RWHP normally aspirated and street driveable. Weighs about 90-100 more than the aluminum, but bulletproof if you buy it right: add SCrs, nitrous or heads and cam or all of them together. Keep it below 900 RWHP and the motor isn't the problem. You'll rip the rear end out of it, but, hey, that's only $3k to fix.

GMPP LSX cast iron block. A new offering from GM. A decked LS7 block in iron, about 115 pounds more than stock. You can stroke it up to 500+ cubic inchs. Aftermarket internal parts will be expensive. I'd guess a full house blown motor with the best heads available and a SCr, etc., would cost $70K in the car but deliver 1300 RWHP. Be my guest -- I want a video as long as I'm in another state when you let out the clutch.

 

I was prepared to give my 2 cents, but don't think I can really follow Lee with any additional information. All I can say is no matter what route you take if you want to get anywhere close to 600HP you MUST have a built bottom end or that motor won't get you too far. Good luck and let us know what you do.

 

thanks lee, that was an amazing answer. i'll probably get the ls7 crate then as i definitely don't have that kind of money and i'm in love with the 427's. i can probably get a good deal on it through my dad's friend at the chevy dealership. if i do go that route is it possible to retrofit a tiptronic, or whatever gm calls it, automatic or dual clutch or whatever ya call it transmission?

 

I still think the best bang for your buck is a supercharger. You can get a smog-legal setup that adds about 150 HP for $7000. That's 500 HP total - much less than an LS7 and still very reliable. I'm not sure where you live, but around here, A&A Corvettes (Southern California) and Andy (owner) is the C5 guru of enormous proportions.

 

A supercharger gives you more bang for the buck: typically you can get a incremental cost per HP of around $50 (100 additional RWHP for about $5000).

The stock lower end and pistons can take somewhere in the neighborhood of 465-485 RWHP (typically about 7-7.5 lbs boost -- you generally have problems getting a $5000 kit to do this but spend a bit more to get one that could blow up to 8 lbs and you're still under $6500). At that level if will be fairly durable (if you don't abuse things). That corresponds to about 530 flywheel so you'll have a bit more than a stock ZO6.

going to 600 Hp however, would require boost and torque that would tear the lower end apart. Thus there is an increment of power addition that is very expensive: going about about 550 HP means you have to rebuild the bottom end -- as long as you are doing that you might as well do a stroker (its costs almost nothing more) to get more cubes, then Sc it is you want.

 

i want to keep the ls1 in stock condition and be able to put back in later so i can say it's stock when that will raise its value. so i think i'll save up and get an ls7 then do some work on that. i would supercharge it, but i think it's just somehow cooler to be n/a, don't ask me why. so if i do put the ls7 in, can i retrofit the toggle shift automatic to the car as well.

 

You can do anything if you have enough money, including retrofit the transmission. But it would be expensive. Of course, a supercharged LS7, done right, won't be cheap, but the transmission with paddle shifter, I don't know. You'd have to reto-fit a steering wheel with paddle shifters and I have not seen that done. Also realize the LS7 is not sold with the auto trans (doubt it can take the torque).

 

i don't want to supercharge it at all, but what kind ofpower do you thinkmy transmission can handle and the new corvette transmissioncould take. i'd like to stick to factory parts even if they are not from the C5. i know i've seen an ls7 in a C5 on this forum or another and i don't remember the guy saying anything about a transmission rebuild, but it was probably manual, which i learned to drive today on my friend's jeep. woo hoo.