I have been trying to find factory specs for the 67 300-2bbl. Like true compression, valve size, cam lift, piston CC, head CC, rocker ratio. I have a 67 Special with a 3 on the tree and was toying with the idea of a slight cam upgrade, I already have a 65 4bbl intake coming with a 500 Edelbrock carb. The car already has true dual exhaust. Also what gears would a 67 3 speed manual Special come with? Ive heard of 2.93's but also 3.23's.
The 1967 Buick Chassis Manual has some basic specs, I don't think you will find specs for the head and piston cc's, or the stock cam specs. My guess on the heads is ~53cc? The rated 9.0:1 compression is probably less in the real world. The only way you will know for sure is if you measure everything yourself.
Here are the NHRA specs: http://wildaboutcarsonline.com/memb...nts/9990391908069/1967_NHRA_Specs_-_Buick.pdf The head cc of 54.9 is likely the minimum after milling the head , production heads will be more. The deck clearance of 0.010" is also the minimum allowed for NHRA racing, production will be much more, maybe in the 0.050" range. I'll guess 3.23 for the rear ratio, 2.93 would be the automatic. I can look up 66 specs but I don't have the 67 info.
Use a phone GPS app to check the mph and record the tack rpm at 70 mph and use an on line calculator to see what gear ratio you have. You will also input the tire size.