Quote:

terry

so if im reading the document you posted correctly

it shows that the t-quad and avs ARE the same height, is that correct?

because the avs was used on both 69 383 and 440 motors

and im sure that the small round air filter is taller, than the large oval air filter, i havent measured them but id guess about an inch different in height, which therefore would explain the height difference in the base

i did just measure a t-quad and ave and they are the same height from the bottom to the surface where the air ceaner sits, so the carbs are the same height

i remember years ago when ken s was at my place looking at 340 shaker baseplates and i thought he was telling me how he thought the 71 tquad base was a different height then the 70 avs base

Yes the thermoquad and the AVS both measure 3 1/4 height but the thermoquad was factory installed with the thick base gasket that the AVS does not use which accounts for a height difference.
The Fram CA305 ( Chrysler PN 2863349 ) is not taller than the oval Fram CA332 ( Chrysler PN 2863186 ) as both measure 3 1/8.
Pictured are both.
And yes there are two different 340 shaker bases, the 71 short one 3512765 which was the same as the rare, seldom seen 440-4V shaker base and the taller 3512764 1970 340 base.
383 shaker base is taller again than the 1970 340 base.
And yes the AVS was used on both 383 and 440 in 69 but the 383 used the deeper neck of the two bases.
My guess would be because the intake manifold is a bit shorter on the 383 than the 440 or it could be a hood to base seal issue.
If you have one of each manifold, perhaps you could check for us Tony.

7415159-zzzzCA305.jpg (402 downloads)