sinful7

iTrader: (1)

I have a 2008 hummer h3 alpha with the LH8 5.3L in it.

someone told me as I am searching for parts for my nephew on his build that my motor being a Gen IV 5.3L has the internals of a Gen III 5.3L motor is that true??

I know sensors etc are in new spots and updated but are the crank pistons and rods truly the same? not that its a huge deal cause these motors have been super reliable and my motor is stock and i have no plans to not keep it stock.. this is just for my knowledge only guys.

essentially what I gather is 5.3L rods from a gen III, will work in a Gen IV 5.3L just the same, however are not quite as strong and of course if one would want to go to the gen iii rods if i do have the thicker ones like I think I do, the engine would need re-balanced of course.. so please correct me again if I am mistaken.

I just really thought it was odd when I was told by yes AUTOZONE as I am trying to find a set of ls1 pistons for my nephew.

They seen my hummer outside and said well if that's an alpha (I guess they assumed the pistons was for that I guess) he said "Well the rods and pistons and crank in ur H3 alpha are the same as in a 2002 Silverado gen iii 5.3L motor". and that there is no difference except mine is simply newer..

i didnt argue with the guy as I could care less as I wasnt there for that. But it made me think maybe hes right, even tho I didnt ask..

So I figured I would ask you guys who flat out know... Since it kind of sat in my head on my drive home.

So for just piece of mind sake if I would some reason rebuild my LH8 5.3L gen iv motor in my H3 alpha, I technically could use stock oem gen iii 5.3L, or Ls1 rods in it pending I re-balance the assembly correct??

KCS

iTrader: (20)

I doubt it. I got a 2009 LC9 aluminum 5.3L and it had the Gen IV rods in it with flat top pistons.

sinful7

iTrader: (1)

ok so if i for some reason wanted to rebuild my motor for whatever reason. I still could use gen 3 rods in my gen iv 5.3L? or would I need to use gen iv rods regardless?

But thanks for letting me know about the gen iv internals I have, I thought I did but it was one of those questions where I couldn't really say he was wrong to his face cause I could see it being possible. I just didn't care. haha

zildjian4life218

AFAIK Gen III rods are all press fit. GenIV are floating so you would need to keep the rods consistent with the piston wrist pin type and the existing rod.

sinful7

iTrader: (1)

Fair enough guys. I appreciste the info. Its do able but not just a simple ordeal. Pistons would need to match as well. Ok fair enough. Thanks gents!!