I'm getting my 1986 Mustang GT ugraded over the winter. It's already got an Autopower roll cage welded to the subframe connectors, Griggs panhard rod, torque arm & adjustable trailing arms with a 3.73 and Auburn road racing diff out back. The front end is getting a new tubular K member, coil overs, and my police/taxi A arms are getting replaced by tubular units. I'm going to mount the engine 1" back and shorten my aluminum driveshaft as well.

I'm replacing my .030 over 5.0 original short block, J302 heads and tubular GT40 Manifold combo with a 363 Dart SHP short block with a forged crank and upgraded rods. I'm shooting for a 3500-7500 RPM range, 550+ hp with a solid lifter cam and 11:1 compression ration. Headers will be full length 1 3/4 inch and 3" exhaust with an X pipe. I'm getting a custom ground cam, and am looking at AFR heads. Would ported AFR 205's and Trick Flow Box-R manifold and 90mm throttle body be my best bet? Maybe the Trick Flow-R 12" runner non-box with a 90mm throttle body would be a better combo for Open Track events? Would AFR 225's be too big?

225cc head not to big when the rest of the engine is put together right with the right cam guy behind it all...

My choice would be the AFR 205s or even TFS 205cc heads, with R series intake not the Box R. With a circuit car you want good airspeed through the inlet tract which will give better throttle response & make for a faster car over peak HP.