I am a fan of Oldsmobiles and your group. I search for information from time to time on these cars. A recent search of NHRA engine blueprint specs I found something I don’t understand if I am reading it correctly. For the 1966 (330) engine it shows two different valve sizes. One for automatic and a different size for standard shift cars. I am curious if anyone has come across this before.

Deck
HP Disp Cl Valves Cam Lift Gasket Springs

155 250 .0106 1725/1505 388/388 Outer Only
250 330 .002 1880/1567 387/388 Outer Only
260 330 .002 1880/1567 387/388 Outer w Damper
310 425 .003 2000/1629 430/432 Outer w Damper
320 330 .002 2000/1629 430/432 STD Outer w Damper
320 330 .002 1880/1567 430/432 AUTO Outer w Damper

 

Apparently those were the specs supplied to NHRA from Oldsmobile.

 

Oldsmobile routinely used different engine internal specs for the AT and MT motors. One classic example is the 1970 W-30 motors. Only the MT engines got the 328/328 cam. The AT engines got the 285/287 deg cam. Despite this, both were rated at the same 370 HP. You can ask the Olds marketing department how that was possible. Another example is the 1972 442s. Only the W-30 motors (with either trans) and the MT engines in non-W cars got the 2.070" intakes. AT 442s only got 2.000" intakes. Cam profiles were also different between MT and AT engines.