I made 245rwhp and 255rwtq on a superflow (259.9rwhp dynojet comparison) with a stock mark8 DOHC w/ `96 cobra intake/tb/exhaust manifolds and IMRC deletes.
I had a bad exhaust leak from the passenger header gasket at the flange to the H-pipe, a CEL illuminated for system rich and PO301 (missfire cyl 1), BBK fenderwell intake with K&N, stock air tube after the stock mark8 MAF, BBK 2.5" catted h-pipe and flowmasters welded into the stock catback, so pretty much stock besides the IMRC deletes that I made.