Hi folks! i have a mildly built 350 from 74 or 75 in my monte and i am trying to figure out what heads are on it. I looked for the signature double hump of performance sbc heads but instead there is a recessed groove where the double hump or other marking would be. The only numbers i could see are 8535 on the front of the passenger head. Motor is in the car so i would like to dissasemble as little as possible. Attached is a shitty diagram i made. Any help would be appreciated, thanks in advance. -Ethan