Re: Need Cylinder Head, '34 8. What Yrs would be Interchangable ?

Posted by Owen_Dyneto On 2020/5/18 7:51:33

Typically, if they have a number of any type, the L-8 motor heads will have a casting number and not a finished part number. Depending on the factory machining operations after casting, a single casting can produce the low, standard, and high compression parts. The same can occur in subsequent service life, the simple act of resurfacing a head a low compression head can create a standard or high compression head, and that's why casting numbers were more useful than part numbers.

In any case, assuming they were not later altered, if you really wanted to, you could differentiate the low, standard, and high versions by the volume of the combustion chamber, IIRC the specs are given in the Motor Assembly Notes blueprint. In practice it's rare that there is a need to do so.

Other than the slight change in engine performance, you make no changes and do no harm by installing a high compression head on an engine originally fitted with a low or standard compression head, and visa versa. In a practical sense those variants are all interchangeable. In the final analysis, assuming you want correct physical appearance, any of the 1933 or 1934 heads for a 320 engine will be fine.