I believe 04' was the year GM went with stronger internals on the LQ4, so I would shoot for an 04'+ long block

 

I thought that it was 05...maybe someone can confirm this...

 

so if i have a 99 with a 4.8, and i go with a lq4 from 01 or newer what do i need to make it work with the trans i have now? what about if i go with a lq9?

 

It depends on what transmission you have, as the '99 4.8L with a 5 speed would have came with a long style crank as well.

 

i should have read and searched more before i first posted. i have the automatic trans, so if i go with a 01 or newer lq4/lq9 i will be able to use the 4l60e i have. if i go with a 99-00 lq4, i will need a 4l80e or manual trans. correct so far?

if i swap with a newer drive by wire engine, all i need to do is swap intake manifolds from my 4.8 and that problem is solved? i'll also need to swap the flex plate from my 4.8 to the 6.0? is there anything else that i would need to swap or should know before i really start searching for an engine? does if the vehicle it comes out of being 2wd or 4wd matter? mine is a 2wd for reference. any other tips, tricks, knowledge etc is appreciated. my goal is to upgrade the whole drive line to make and support a reliable 400-500 rwhp. i want something that i can drive every day in traffic to work, but have something thats lots of fun to do it in.

 

You have it right, and the engine doesn't care if it was hooked up to a 2wd or a 4x4