440 Cam selection help

Put on the better flowing heads. It will make meaningfully more power even at your level. Consider a good valve job before install. It will pick up the low flow numbers.

I like the MP 528 cam too. I would not put a new HFT in anything today, especially a fast rate HFT.
Not sure if I want to go solid, the idea would be regrind the old cam and lifters hopefully not run into the break in issues with the new cams and lifters people have been having. Not sure how it will work out but I have a little more faith in the cam and lifters from the 70s.