Sweet64

Hey there everyone. I got a 1964 olds cutlass with the a high compression 330 with number 1 cylinder heads, all original motor and heads, I have a chance to pick up a bare set of 1972 number 7's and was curious about the pros and cons of the these heads, and will I have a problem with bolting up accessories,non a.c. car, as far as alternator , power steering pump, intake/exhaust manifold goes?. These #7 heads are bare stock, These are intended for a spare set for my car, we do our own head work, so nothing gets done outside of our shop. And is anyone aware of any aftermarket aluminum heads being offered on the market that fit the 330..appreciate everybody's time and opinions, this car intended purpose is just for cruising and car show hunting, and it sure has a knack for finding damn good tenderloins!!

Fun71

The '72 7A heads (7 heads were used in '71) may have larger combustion chambers than your 1 heads. If so, that so that would drop the compression ratio. They should bolt up to the block OK. If the price is right I would buy them just to have them on hand.

As for aluminum heads, the only ones out there are designed for big blocks. You could bolt them on, but there would likely be issues to overcome such as intake port matching and chamber volume.

Sweet64

Thanks for the reply, I was curious about that combustion chamber size on those #7's.. I've seen a few different numbers.. Thanks for the heads up on the aluminum heads ..I was figuring there where out there for the big blocks.

olds 307 and 403

The 7 heads have a larger chamber and conventional Olds rocker arms vs the 64 only shaft set up. The Procomp heads are supposed to work really well on the SBO and are cheaper than the Edelbrock head. Once inspected and properly set up by a good shop with quality parts, they are a good head. One issue with Edelbrock or Procomp head is the 77ish CC combustion chamber compared 60-70 CC, depending on 330 or 350 and who you ask, early SBO chamber.

Sweet64

Great info here guys,thanks for taking the time to reply, any chance those #7's came stock with diffrent size valves? Thanks

Fun71

I had a poll on ROP a while back asking folks who had actually measured their 5, 6, 7, 7A heads to post the numbers. Most were ~68cc with a couple reporting 64 and 66, but those smaller numbers were in the minority.

Sweet64

Very nice...I was figuring they landed in that 68-70cc range..thanks again for the info ...