Factory Data- Combustion Chamber Volume, 70, 71 351 heads

I was searching for previous posts I had made, and discovered this, so I thought I would respond...4 years later!

I have been unable to find ANY FORD LICENSED DOCUMENTATION such as a service/shop manual detailing combustion chamber volume as well as camshaft information for a 351CJ or 351BOSS. People are quoting information, but are never able to produce the Ford printed document. That does not mean they are wrong, it just means there is no manufacturer trace for the source of the information.

I do have a 70 & 71 shop manuals. 70 lists 351 4V and 302 Boss. 71 lists 302HO, 351 4V. No mention of a CJ or BOSS unless it is in a note on the page that I have missed. No mention of mechanical lifters. 302 Boss does indicate 7/16 threaded stud, page 21-04-35 under cylinder head. No mention in 71 manual for 351.

70 Specs
302 Boss, page 21-04-35 lists chamber combustion volume as 61.3-64.3cc.
351 4V, page 21-05-28 lists combustion chamber volume 61.3-64.3cc.

71 Specs
302HO, Page 21-21-34, 61.7-64.7cc
351 4v, page 21-22-28, 64.6-67.6

The specs do not indicate if the spark plug displacement is taken into account. I measured the combustion chamber of my heads without spark plug, cast with the following identifying characteristics:

1. 4dot
2. D1AE
3. GA
4. D Shaped quench head
5. Non machined pedestals

and I got 68cc. If anything, I was probably a little over but not by more than 2cc.

I understand there are errors in manuals/documentation. In fact, my 70 Shop Manual indicated 302 Boss combustion chamber volume as 6.13 - 64.3, so we do need to be careful. But I would sure like to see a shop manual for the 351 Boss.

This site has some nice photos:

http://mustangtek.com/heads/Heads.html

Interestingly, for 351 Boss they list combustion chambers at 75.4 but do not show combustion side of head. Pedestal is lower, and the thread appears 7/16, but it doesn't look as if the pedestal was machined.

Photo of my chamber: