[68 TT]

If it is anything like the 4L80 then the stock torque converter is a huge HP robbing pile of scrap metal. An aftermarket torque converter is a big improvement in HP to the wheels and gas mileage improves too.

A 2600 to 2800 rpm converter sounds just about right for the lift & duration you have with that cam. It won't like a stock converter at all.

2000 rpm would be the least stall I would put behind an L92 engine with that cam profile. It will be down on torque from a stock cam below that and needs the help getting the truck moving with less power to the wheels off idle.

That cam has pretty similar specs to what I ran in my 427 and your heads will flow pretty close to what a rectangular port big block does if not more. It will really plant you in the seat when you get it to 3000 - 3500 rpm and the torque curve really starts to take off.