FWIW, one of my customers is running the 572-13 heads with 1.7 Jesel rockers and a .775 lift cam, using the spray bar valve covers.
3 seasons, no problems at all.

another has a 622 with 600-13 heads, .880 lift cam, triple springs, 1.75/1.7 rockers.....no problems with the spray bar oiling.

all im saying is.....there are plenty of people out there using it succesfully, so its not like it wont work.

both of those motors are running ball/ball pushrods.

68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads