I'm seeing some discussion on FB regarding the presence of G heads vs the Ga on early (thru Dec 71) 1972 big blocks that utilized the bigger valves (V and X codes) . This is the first I've heard of this and thought I would float the question here among this group. Anyone seen this on a known original early car? Several owners claim a G on one side while a Ga on the other bank.

Could this have been driven by a shortage of big valve heads with hardened seats ? If so why would they mix the heads on the same engine? Production rate rules in a factory I know, but would this really be a factor on low production rate vehicles.

tc

 

Over a hundred views and no body has heard of this before....hmmm. I was afraid of that.

 

my sbo 72 has 7 heads 7a heads are commonly associated with 72s

the car was built in sept 71.

it alos has a SS rearviw (not black like 72s) and no seat belt light on the dash.

Im gonna guess due to the strike and other factors 72s can be a mix of of common parts.

 

I have a U code VIN 72 442 and while when I bought it there was no drivetrain; I was lucky enough to get a '72 Ga head 455 out of a local junkyard for it. Ga heads flow as well as the rest of them but aren't as sought after as the Cs Ds and Fs. There's several people posting here who probably have a pair in stock for sale. My own reading into the issue shows that standard vehicles, luxury cars and automatic 442s got the small valve heads. 4 speed and W30 442s got the large valve versions. There was no special W30 head in '72. GM used what they had in stock especially at the beginning of a model year. . If your '72 has the original engine in it with G heads then leave it alone.