Recently jumped ship from an internally stock RB25 as she was about to grenade herself.
New specs:
S2 RB25 head fully refreshed. New OEM lifters, 268/272 9mm camtech cams, welded and mated to a RB30 block and external VCT oil line.
RB26 ITB setup with brand new OEM throttles and adaptor plate mated to the head. Controversial to what people bang on about these adaptors, I have never had a issue nor one leak.
Forged RB30 block. CP flattop pistons, h beam rods, ACL race bearings, N1 pumps, OEM balancer, larger sump.
Gen II GTX3582r .82 with a 50mm pro gate welded onto the housing. Hyper tune 600 x 330 x100 cooler, 3 inch exhaust with waste gate plumbed back in.
1000cc injectors, 044 external pump running of the surge with a in tank denso
Link storm ecu with a bunch of sensors monitoring the engines vitals.
Plenty more I have missed, but you get the idea.
E85 made a maximum of 363kw but the Link kicked in fuel cut as we didn't have enough fuel to feed the engine. Detuned to the same as 98 at 340kw.
Larger fuel pump/s and possibly injectors and I'll go again. For now I am going to enjoy it for what it is!