Happy TG ALL. Here's my 2 cents...You have a small motor with "big" heads and low compression (as you admit, it's using pieced together parts) I'll bet the biggest contributor is a dip in the torq curve not allowing the converter to drive thru to it's highest stall at the line. I think it's something a camshaft change could fix, might help advancing the current one. Among other 'minor' issues contributing to the problem that have already been discussed.
That's exactly what I was thinking.
I've dynoed a couple of moderate CR 440's with -1 heads and slightly too big of a cam, and they were pretty darn weak in that rpm range.
My feeling is in a combo like that if the cranking compression isn't absolutely high enough for the duration of the cam, that hole in the TQ curve will be pretty deep.
I don't know the specifics of your converter(or cam for that matter), but assuming the cam is close to 280@ .050, and I were looking to help this situation without digging into the motor, I'd try having the converter set of for more free speed and a flash stall speed of about 56-5800 and run the two step at 5000-5200.
