/6 4bll intake.

All slant heads bolt onto all slant blocks no matter the displacement. The ports are all the same size so a 225 head will not flow anybetter than a 170 head. The "drool tube" heads are measurably lighter(I believe it is 10-15 pounds) than the "peanut" heads. Swaping heads will not give you hydrolic lifters, you would need to replace the cam and lifters and find a head from an 80's engine for the non-adjustable rockers.