The BOSS 302 heads are known as
"Cleveland style" heads as they are based on the head designed for the 351
Cleveland engine. As the 1968 Tunnel Port engine turned into a disaster, someone at Ford
Engine Engineering got the idea to put a set of Cleveland heads on a Tunnel Port block and
thus was the beginning of what would become the BOSS 302 engine.
The Cleveland style
head featured a staggered, canted valve arrangement. This provided more room for larger
valves instead of the standard side-by-side arrangement.
You can see the valves
are canted in this picture.
casting part numbers:
1969 - C9ZE-6090-A or C
1970 - D0ZE-6090-A or B
The BOSS 302 heads
used some of the biggest valves in the industry.
1969 Intake - 2.23 inches, Exhaust - 1.72 inches.
1970 Intake - 2.19 inches, Exhaust
- 1.72 inches.
Said to be "overvalved"
for street performance.
again you see a casting with a D1ZE part number. Parts made from tooling for the canceled
1971 BOSS 302.