Didn't like my answer on Honda-Tech.com, huh? Check out the wiring harness to the distributor, because the drive vs. reverse thing is important.

With all the stuff you listed (B18B, TP tubular equal length manifold, Garett T3, HKS WG, HKS IC, HKS BOV, HKS Filter, HKS SAFR, JG TB, SK2 CG, SK2 IM, AEM FR, AEM FPR, RC 310cc, MSD Inline FP, Vortech FMU) I bet somethings pushing on the wiring harness & you didn't leave enough slack for the engine to move.

If your engine mounts are going/gone bad, your engine will move more than it should when you put it in gear. Drive & reverse make it move in opposite directions. In drive the engine wants to lean back towards the firewall, in reverse it wants to lean forward towards the radiator.

Follow the wiring harness from the distributor, look for anyplace where it can pull itself too tight when the engine moves. There's probably a busted wire that only opens up when its stretched. That'll be a PITA to find.