I am running a 511/tf 270 combo with a 5 speed. But I am using a proform 1050/4150. I think you about ar the limit for taking advantage of the 270 heads with a hydraulic roller. I am running a 265/269 .660 on 108 solid roller.
I do have to be going 75 mph to use 5th gear. But it’s not a big deal. I have 4.10 and a 30” tire. So I don’t much need the overdrive. The car has great street manners for a 750hp engine. I put 800 miles on it this summer. The gas mileage is terrible. And it does buck a little trying to idle through a parking lot. But it’s completely maneagable. It is a blast to drive.