Estimating Cam Specs

I acquired a fresh shortblock that I have used in my car, and would like to know if there is a way to estimate cam specs from other information. There were no markings on the end of the cam, which is a flat tappet hydraulic. It idles around 950 rpms with 15 degrees of initial timing and only pulls 8 in/hg at idle. It sounds pretty rowdy and pulls against a 2,200 stall converter to the point where I think I'm going to have to get one with more stall. Its a .030 over 454 with flattops and '68 closed chamber heads, compression is around an actual 10.1. I'm not goint to pull valve covers off a perfectly detailed engine, but wonder if there is a way to ballpark estimate specs based on this info. If I am going to replace the converter, I'd like to get it right on the next try. I was told it was around .540, aint' no way this is true based on other big blocks that I've owned. All advice appreciated.