Being an 88, they would almost have to be hydraulic, wouldnt they?Oh, and streets, if memory serves me right, the oldsmobile engines were a 78 option. Your talking of the 403, I hope. Anyway, if the 403 is like the 403 in my car, they are almost dummy proof. Actually, i think the same design was used on all the small block heads for rocker arms. Wasnt it?