Whats the biggest size engine i could put in my 04 grand prix gtp ???

I know the 04 gtp has a 4t65e tranny not sure if it is HD ...do you know if it is???

I think the 2.93:1 MN7 4T65E-HD trans came in both the supercharged GTP and the V8 GXP.

Ok cool thank you ...i recently got the trans rebuilt and they beefed up the internals some ...... do you know if same motor mounts would work or would new ones be needed?

I mean..technically I think it would be a LS7, or a stroked out gen 2 small block. V8's go against the 4t65E transmissions pretty easily with an adapter. I've never seen a big block Chevrolet against one and that would likely be short lived anyway. If it would even fit in the engine bay.

The LS4 is a great engine paired with a crap transmission (the 4T65E and 4T65E-HD). If you can find the 80E, use the kit to interchange it onto the LS4 as it will hold up better than the 65 series including the HD variant. The 65E is meant to handle the load better from the V6, hence why i recommend finding a used 80E and rebuild it if needed before using the kit to slap it on the LS4. Its worth the long term investment, trust me my friend!

I've got a 455 rocket with a fwd transmission out of a GMC RV I would like to frankenstein into my 02 GTP.... I know it would be some work... But I don't see why anything is impossible... Maybe one day it will be at the track!