I'm not sure how much angle on the lifter bottoms there are between stock and low taper Not sure how to measure them either i have had several sets of the early (Pre 1968) Mopar solid Hemi lifters reconditioned by a company in Seatle, WA Maybe you can have yours done too locally
I think the low taper was a 21” radius while the standard was 18”. But it’s been a long time.