Rat66

Been a little curious about this lately so I thought I'd bring it up. I know it's been talked about before but I've done a lot of searching and I always come up with head comparisons (5.3 vs LS6, ya know?). I was just curious. I've seen a lot of people swapping their LS1s for truck motors in boosted applications. I understand the 6.0, it's bigger and can go to 408, I'd like to have one to do a 408 eventually. But why swap the LS1 for a 5.3 or 4.8? Is it just an issue of compression? Are the internals stronger on the truck motors? I hear a lot of people saying once you hit about 500hp on a boosted LS1 or LS6 you're pretty much maxed on your internal strength but ove also seen turbo 5.3s going up to 750hp+ and taking heavy abuse at the track with 100% stock internals.

The real reason I ask is pretty much explained in my signature. I have a 2000 T/A that's ready for boost, just need a rear end and trans rebuild kit that can handle the added power and I'm set. It's got an LS6 swap from a CTSV in it and I plan on keeping that rather than going to an iron block. I figure I could've found my answer if I really searched for a few hours but this way I also get the added benefit of meeting the community. I'm still trying to find my place here and would love to get a chance to chat some. Thanks in advance

wildcamaro

iTrader: (15)

Truck blocks are iron compared to aluminum on an ls1/6 block...ls1/6 have higher compression than any truck motor, sometimes people swap on truck heads to raise compression at the sacrifice of smaller valves and ports unless they work the truck heads...people start forced induction builds with iron blocks which is smart, but if you already have an aluminum block, especially an ls6 block I wouldn't be afraid to boost it, just make sure you match lbs of boost to your compression ratio/intercooler/etc...unless you plan on making ridiculous power the aluminum block will be fine...if you wanna run a lot of boost a common option is to swap to 6.0 "317" heads in order to drop the compression ratio while still keeping the same size ports as your ls6 heads...

RezinTexas

if you're boosting and only want to go fast in a straight line, then a truck motor is what I would do. Most go for the 6.0 just for the bigger bore, but otherwise the engines are identical between 5.3 and 6.0. 4.8 has the shorter stroke also. The 5.3/4.8 can be bought for under $500, while you'll be lucky to find a good 6.0 for under $1000 in most areas. The stronger connecting rods started in 2004, btw.

Rat66

Mk thanks. Yeah I've got the LS6 with 243 heads. I had planned to swap on 5.3 heads when I was looking for my T/A and when I found one that had the 243s already I scrapped that idea. I'm thinking once I get to it I will be looking for a procharger or vortech. I'd love a twin screw but they're really expensive and require a good bit of modification for these cars so I think that's out of the question. At least for many years lol
Thanks again guys