Here's some info I managed to put together about the carter tall jets. Flow is without the metering rod.

Part#..................CC..........mean.........holley equivalent

120-265S.......320-326cc......323...........63
120-264S.......337-343cc......340...........64
120-268S.......360-366cc......363...........65.5
120-267S.......380-386cc......383...........66.5
120-263S.......400-408cc......404...........67.5
120-277S.......417-423cc......420...........68.5
120-293S.......436-444cc......440...........69.5


The holley info I got from here:
http://www.barrygrant.com/bgfuel/defaul ... ifications

and did a rough extrapolation for the holley equivalent above.
My jet is a -263S, and a .067 drill bit fit, a .070 drill bit didn't. A holley 67 jet is .068 and a holley 68 is .069, so area and

Flow does seem to be a linear relationship to jet area.

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

This is good info, thanks for posting it.

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