u need to start with the stall converter. don't get crazy though, 2500 should do you just fine. man with 4.11 gears i would think it would turn them over no problem. had to put a stall in mine and thats what i went with...2500. mine will roast both tires till let off the pedal!but i also have a mild hydrolic cam and gt40 heads that have been ported. not sure about tunnel ram, not to familiar with them, but i have an edelbrock rpm on mine, good luck!
Had a friend with a 68 Mustang running a 4V Cleveland with a mild cam, 9.5:1 compression, dual quads, 3.89's, a C6 and no stall just a stock converter and you couldn't keep the tires from spinning. You can get it dialed in and keep the intake, just take it one step at a time so if it gets worse you know what did it.
