there aren't too many aftermarket heads out for the SOHC motors. There are however several places that will port and polish stock heads and stuff them with new cams, valves and springs. Check out VT, Fox Lake Racing and Anderson Motorsports. Those guys are doing some awesome stuff with heads. Also, check out Cranes cams for the mod motors, you can go as wild as you dare and make some kickass power and not get boosted or juiced. Also, a cobra intake will not fit on the SOHC intake. On the old 5.0's you could do the swap, but not on the 4.6L's because the GT is a SOHC and the Cobra is DOHC with completely different intake manifolds. If you want to swap intake manifolds, there are a couple really good ones out, I just remember who makes them right now.
