[Held for Ransom]

I'd be interested in a picture of the inside of the air cleaner base.

Crankcase vent pipe should be the same (other than a notched end inside the valve cover) for both years in reference and has like a 95 degree upward slope.

On a base I purchased for my '69 Firebird years ago, I had laid the air cleaner flat on the edge of a table and measured from the carb. ring to the table and it was like a 1/4" difference between that and my '70 GTO measurement. I think I used a veneer caliper and measuring from the top of the folded over ring to the table was like 0.95" (supposed '69) vs 0.70" ('70 GTO).