My lifters are NOT made by Comp, they are made by a private manufacturing facility to my specs. The COMP 8043 lifters cause issues on blocks with deep chamfers to the top of the lifter bores as the oil band and pushrod oil hole are uncovered and full lift, we fixed that for 95% of all production blocks out there. Plus we use a higher quality axle/bearing material than the Big guys making lifters today.
Ours drop in without grinding, but much like the 8043's the head have to be off the block to get them in.
Pro Sports are $480 BBM and SBM and I use them upto 650# spring pressure
Pro Plus are $580 BBM and $615 SBM for 650# and up