rrcredline

Hello BH Yes they are. I have the press steel type, cast iron type RB20-25 and fabricated type RB30 and they are all the same bolt pattern to the block. I used the RB30s for no other reason than I wanted to. Nigel

I have done the RB25/RB30 (for a non turbo RB30DE) conversion myself at home using the R33 RB25DE head. Used the RB25DE pistons which gave me 10:1 compression The easiest head to use is the R32 Skyline RB25 non vvt version. Perfect water gallery alignment BUT slightly smaller intake ports. The R33 RB25 VVT head only has a minor front water gallery mis-alignment but is so minor most people here in NZ don't worry about it. This head has the bigger intake ports and VVT for slightly better performance. I modded my slightly at the water gallery in any case... http://www4.wave.co.nz/~lakewood/Skyline/R33_head.htm The RB26DETT head is the ultimate head to use but for most its to damn expensive to use. This could be the head RIPS is quoting. Also his price will offer very reliable 600hp. Not sure its as easy as just popping a RB25 head on and getting 600hp without a whole lot else than upgrading the fuel and turbo and having it reliable.. Nigel