Dear Dick;
These are 12 port heads too. This design (the orginal) circa 1948, are for the 216/235/261 engines.
Larry means; "the only 12 port head for the 250/292 engines".
Both of these(early/late)are Mfg. in California and very expensive. Generaly for racing or the 'hard core' Chevy 6 fan etc.
If your new at this, I would say your money would be 'better spent' elsewhere, as many other engine mods are needed to make these heads work right.
There are driving restrictions as well.
Good luck, John M., #3370
