Percent of lost lift due to 58 degree lifter angle?

I don't think lannon that much lift on my future W5 build. But I can certainly understand where your coming from.
I'll be keeping lift at a max of ,650 or less.

Loved that motor( W5)
Modern cylinder head in the Detroit area has a very good cnc program for that head.
I sold my car with the 422w5 in it about 7 years ago to a guy in New Jersey. He has been 9.60's at 140 with it on 002/003 leafs. Currently weighs about 3220
The heads were hand ported and finally became sprinklers leaking. Modern CNC'd a new set of Blue plug W5 heads he found and the combo was down only about 15 horse from before( with way more integrity) with that CNC job.
They do very nice work