Quote:

---

The 308 head is not the same as the 302 with bigger valves.

As said, the 302 is a closed chamber head, that will give you an easy compression boost on a 318.

The 308 is an OPEN chamber head, just like any other 360 head. It is the best flowing iron head until the 1992 Magnums came into production. The main improvement over the earlier 360 heads is the exhaust port design. Downside, is that installing the 308 (or any 360 head) is going to drop your already low 318 compression even lower.

For a low budget, mild build, go with the 302's. If you have money to mill the deck, upgrade pistons, then go with the 308's. The 308's are typically much harder to find than the 302's.

---