casting number is normally on the flange the bellhouse bolts to, top of drivers side .... post it and I can prolly tell the year range .... if it has the mounting bosses on the side it's 58+ .... if it has a neoprene rear main seal it's 59+ .... all 283's originally had the tin can filter, if it doesn't, it'll have an adapter added, the spin on started in 68
Bill
