Wild stab in the dark... EFR 8374. A 7670 would have been too much of a sideways step. It's the logical upgrade after the FP snail.
But, could be well off. A larger FP perhaps?
What sort of single will you be looking at? How much power do you want? RPM limit? Where do you want you power to be?
How long do you plan on keeping the -5's?
I don't know anyone with the new guts TBH. Nicks rear failed at Sandown at 24 psi (was on a 3.0). <10,000 kms total work. My rear was also dead with even less kms done. Both older cartridges though.
@Full-Race Geoff
8374/1.05... Will the 1.45 ass end drop straight on without dump mods or will the snail sit taller?
We tried to have a play last night but without pulling the turbo off bit we couldnt confirm.
250 kw at 4000 RPM out of a 2.6 using -5's? You're going to struggle, mate.
Whats the rest of the setup? Head been touched?
* I would STRONGLY suggest not running -5's up around 450 Kw + at the treads. They will not last!