u dont need to make a new manifold, just go to exhaust shop and buy a t2 flange, or just give them the manifold and get them, to do it. i think a fj turbo is probly too big i have a t25 on my ute and it is plenty, even on 7psi my car went very well without and intercooler, i reckon a t3 would probly be inefficient on an a series motor.... depends on the mods