Are all 5.3's the same?

[farmtruc]

i'd invest in the parts needed for a newer 5.3L, lower miles. Just getting harder to find a Gen3 engine with low miles.

you'll need a 4bolt to 3bolt throttle body adaptor, in addition you'll need to make a bracket for your throttle cable; not a big deal.
knock sensors relcated, like he said.
extend your cam sensor wiring and repin
get the 58x to 24x converter box from Ling.
probably a few small things i forgot, but easy stuff.

btw, i have a brand new 2013 avalanche 5.3L, 100 miles for sale (coming up).

[kerrige]

You can run a newer motor with just the long block. You will need the converter box, cam sensor deal and the knock sensors relocated. No need to swap intakes or throttle bodies. Oh and you will need a good custom tune. It will make a little more power then stock, but you would benefit from swapping to the newer intake etc. It's just a little more simple this way.

[468Blazer]

thanks for the info