6.0L vs. 5.3L
#21
#22
Your gonna spend more money buying a 5.3 and then switching heads, gaskets, etc just to have a 5.3 with LS6 heads. 317 heads flow just as well, and come standard on the 6.0. If u want the cheapest route to 500hp (im assuming your talking crank horsepower, cause there really isnt a cheap route to 500rwhp) get a 2007-2008 6.0 LY6 motor. It already has the l92 heads, it comes in the NBS 2500 and 3500 chevy trucks. It dosn't have DOD or AFM, so you dont have to worry about switching the lifters like alot of GEN IV truck motors. It does have variable valve timing....but you're doing a cam swap anyways, so you ditch the VVT in the process and slap a ls2 cam gear and front cover on it when you button it back up. Now you essentially have a Iron block 9.5:1 LS3, with a hot cam of your choice. Slap a l76 intake on it.....you can still run the truck throttle body and injectors that came with your motor, they fit. Cheap 500hp (at the crank)
#24
either send or exchange the 317's to get ported (west coast cyl heads, texas speed) or just sell 'em on ebay for a couple hundred $$ and buy a set of stock l92 heads for around $900 a pair, and throw them on there with the appropriate rocker arms, and your upgraded performance springs to match whatever cam your gonna run. Throw in some better pushrods too...the stockers are pretty weak. The L92 heads flow pretty awsome stock, although the exhaust side needs some help and benifits from porting. But for your goals and budget, the stock l92's will probably do you fine. But......finding a ly6 is the way to go, you'll already have the l92 heads and save some $$. You can usually get them for under $2000 from salvage yards....not much of a price difference than if you were to buy a low mile lq4 or lq9 from a yard
#26
#27