RB26DETT variant information

Hi,
I am very interested in an RB swap to an early Datsun Z car. My '73 240Z is all original, but I would probably get a 260Z so the 260Z can hold true with the RB26! Also I may get a 280Z and stroke the motor to 2.8L. But nothing badging can't change!

My reason for posting is I am wondering about the differences in the RB26DETT engines. I thought about going RB25DET, for cost, but then I realideb the RB26DETT was not that much more and it certainly has more potential. Is it stronger internally as well?

Also, What are the differences between the R32, R33, and R34 variants. Why would one be better than the other. I realize the R34's engine is the rarest, but It does not seem to cost that much more. I found:

Nissan RB26DETT SKYLINE (GT-R) With RB25DET (GT-S) Transmission $4200

Nissan RB26DETT SKYLINE (GT-R) R32 $3395

Nissan RB26DETT SKYLINE (GT-R) R33 $3495

Nissan RB26DETT SKYLINE (GT-R) R34 $3695

Because of the close price differences, what would be the reason to choose one over the other. Assuming they all have similar mileages, and price doesn't matter since they're all so close, which one should I choose and why? Thanks a lot
Andrew Baculy

also I've seen blue, red, black, and yellow topped engines. What exactly are the differences?

VG30DETT is good because its a Z motor into a Z, but RB26DETT will go in because its still a straight 6, like the car's original motor