B18C5 w/ CTR intake cam or B18C1 w/ ITR pistons & CTR cams?

 

well...
a B18C1 w/ITR pistons will make more compression than an B18C5 engine, hence more power/torque. The B18C1 intake manifold will also no doubt, create more torque over a Type-R engine, buuuut the Type-R engine will flow air much better and have way better top end power over the B18C1, because of air flow characteristics and a few other variables too....

A B18C5 is more tuned (crank/rods/valvetrain/etc) for high reving in comparison to a B18C1 engine...(even if you did just swap out the pistons and cams in a B18C1)

Also the transmission gearing on a B18C5 is a lot better than a B18C1 tranny.