I, too, did one of the T Coupe 2.3's back in the 80's. I used SVO cams and roller rockers, Isky valve springs and I ported the head and manifolds (I used the cast iron exhaust manifold heavily ported and matched) and modified the waste gate to allow 18 psi boost (Bosch adjustable fuel pressure reg). The engine made 290 hp at the wheels on the chassis dyno and would top 155+ at El Mirage with the stock rev limiter. I always felt the engine was being stifled at the sub 6000 rev limit. Most of these engines love to rev and seeing them at 9000 rpm is common. The bottom end of the Turbo Coupe version is bullet proof. One good thing, parts are readily available as these engines are raced all over the world (Google, my friend) and should you break a cam belt, no harm, no foul (at least on the 8.5 CR version turbo) the valves won't hit the pistons.
Rod