Leave the cam and heads alone at least for now. You want a converter that stalls about what mine does. Current FTI converter stalls 5900 behind my 11X head 427 SBC. You should ask Greg as he might adjust it a tad due to your weight, but the converter you have is killing it. You won't see much gain from the heads, and might even slow without a converter change. You will not find better customer service from any converter company. And a lot of guys have been running better with his converters. What intake and carb?
http://fticonverters.com/
1.16 60 ft, 5.29 in the 1/8 at 1850 lbs. And my cam is 285/295 @.050