Engine Swap

[jaroniles4]

Okay fellas this is just a brainstorm. I drive a 2005 gxp and i love it, but i have about how the northstars have some problems and they are a pain to work on. So lets say i blew my engine and i wanted to swap it, would a 5.3 fit and would it mount up to the 4T65E? what would be the best engine do a swap with? just brain storming, but if a 5.3 will fit, i may consider doing it.

[nos4blood70]

No one has done a 5.3, but they do come mated to 4T65s in the LS4 powered W-bodies.

However, it would be easier for you to find another Northstar and stud it rather than adapting a 5.3.

[jaroniles4]

It's just that northstars are so expensive. So it would technically be possible to mount a 5.3 in the gxp?

[1oldman]

I don't think that 4T65e's like 5.3 small blocks. - BC

[haro1225]

It's possible, but it would be a tight fit. You'd be better off using the 4T80 that is mated to the northstar instead of the 4T65 that comes in the GP. Then there would be the wiring and tuning to make it all work together. Not to mention the mounts that would likely have to be made.

[00Beast]

You can't, the 5.3 and its trans are kind of a matched set, so much so that the starter mounts to the trans case, not the engine block, and IIRC the engine and trans communicate very differently (read: different PCM), and I don't think the 4L80E ever came on a PCM that supports the 5.3? Not sure on that, though.

[crash93ssei]

You would spend less money dropping the Northstar and studding it and putting it back in then trying to swap a 5.3 in it. We all want to see a 5.3 swapped in but nobody has done it yet because for the most part it just isn't worth it.

[MattStrike]

I thought the issue was the the 5.3 is too big and the 4t80 is too big, you physically can't connect the two together.