Is there any difference between rb25 engines auto and manual??

[Bobby j]

I have r33 skyline auto but replacing engine from r33 skyline manual. Are they the same or are the cranks different?

[GTSBoy]

Cranks are same. Spigot bush pressed in the back of it is different for auto/man.

I'm not absolutely sure with RB25s, but at least with R32 RB20s, the autos ran at 20° idle timing and the manuals at 15°. This needs to be set correctly with a timing light (obviously enough) and is something that should be carefully checked if doing a swap such as you're describing, in case you end up with a manual ECU thinking it is set at 15° when the CAS is set to give 20° and the extra 5° turns up in the timing at peak torque.