I was referred here from ls1tech. I am curious to know the differences between the different year model 5.3's from say 2000 to the present. More specifically an lm7. I want to get my hands on one. More than likely from a junkyard or off tech. Is there a more "desirable" year model of these motors performance wise? Seems like I read somewhere that the 03+models had better internals, I could be wrong though. This will be for a 5.3l turbo build. Thanks guys! I know my ls1's but jack about these others

 

There are a few varieties of 5.3's
there is the iron lm7
the aluminum l33( lower compression, good boost motors)
iron l59 05+(flex fuel, larger injectors)
and the 07+ not sure on the code on them, but they come with better flowing heads and make more power stock

thats just a quick rundown off the top of my head, you came to the right place some of the experts will be able to fill in some more details

 

http://en.wikipedia.org/wiki/GM_LS_engine

here ya go lots of reading to do, but well worth the time.

 

DING DIng.. Any one you choose will do the job... Naturally the later years you get will have the less miles on them... There are some guys here pushing the l33 to 550+ whp with no probs

 

wrong actually the L33 is higher with CR at 9.9:1 which is why it loves the modified roots blower!

 

Oh I knew the l33 was better for boost and Assumed it was due to lower compression. So do they not respond as well to turbo applications?

 

+1. it uses the same flat-top pistons as the 4.8 as opposed to the LM7 dished pistons

 

I'm assuming that you will be swapping cams, but the 99's have the least desireable factory camshaft.

 

LH6 represent! "LS6" heads, aluminum block, flat top pistons, kinda like a baby LS2.

 

the L33 has those same features. I don't know of any Turbo's L33's but lot's of SC'd ones do fine What is the difference between the L33 and the LH6 VVT or DOD?