13b four port build ideas. 12a GSLSE vs 13BT

[PercentSevenC]

I would not use RX-8 rotors. S5 is the best if you can find them.

As far as 12A vs. TII end plates, I don't believe there's all that much difference in terms of how much porting you can do. What are you planning for the intake manifold and throttle body? If you want to use a TII/RE(W) setup, use TII/RE(W) irons. The reason for this is because the port runners of S4 and later turbo engines go in at sort of an angle so the intake manifold can clear the turbo. REW (possibly also RE?) front plates are better because of the bigger oil pump. Also, the chrome on S4+ rotor housings is better than that of GSL-SE rotor housings, if I'm not mistaken.

If you're going with a custom manifold and throttle body, use 12A end plates and a 12A intermediate plate and mount the primary injectors somewhere else. The reason for this is because the 12A intermediate plate has a LOT more room for porting than the later intermediate plates.