Lower gears and still slugish.

IMO the problem has nothing at all to do with the transmission. It's that big lazy ground Edelbrock cam you have in it. That cam has 308 degrees of total duration so it's a huge cam for a low compression 318 and you need at least a 3000 stall to make it work right. I bet that cam doesn't even start making any power at all in a 318 below 3000 rpm