I do all my motors,lifter valley,lower end and head castings.Quick oil return
and keeps your oil clean.Cheap mod to do if you have a properly cleaned block and some time to kill.
Uniroyal still has the Tiger paws avail.$80.00.Also theres a Republic(made by
Good Year) ultra radial for $58.00 but going obsolete if you can find them.They are both white letter.