rb20 to rb25 possibility???

[sohcslammed]

i have read through some of the faqs and what not, but im just wanting to know how exactly it can be done. i have the rb20 using the ka xmember with jgy motor mounts. the tach is already calibrated for the 20. i will be keeping the 20 trans for the 25. so my question is can i use the 20 mounts or does nobody really have a for sure answer.

[Kansei240sx]

Its all the same. You can use the same mounts.

[bounty212]

i got the same setup as sohcslammed only ive got mckinney mounts instead.what differences are there with wire harness and ecus? i know the pinout is essentially the same across all rb ecus so can u just get an rb25 ecu and plug the rb25 into the 20 harness or are there more complications?

[ryan15]

no you need to swap harnesses, it uses different injectors plugs, and it has vtc

[devil_child]

i thought the tailshaft is going to sit further back by like an inch?

[Carl H]

same mount kit...fits either engine.

[jrd450r]

I may require a different length drive shaft though, as the 20 and 25 trannys are different, the 25 is alot bigger than the 20. You can use a 240sx drive shaft with the RB20, but you cant with the 25. You said your using the 20 transmission though so you may be ok.