Replacement. 3 11/16 x 3 5/8 open plenum irregular hole design, 0.021 thick paper.
The applications show abbreviation codes C2M, C2S and S2M which breakdown as:
C2M = Carb to intake manifold.
C2S = Carb to spacer.
S2M = Spacer to intake manifold.

1968-1968 MUSTANG 428-4V CJ, 428-4V SCJ, C2S, S2M, 2 REQD

1969-1970 MUSTANG 428-4V CJ, 428-4V SCJ, , C2S, S2M, 2 REQD

1969-1970 MUSTANG BOSS 302, C2S, S2M, 2 REQD

1968-1968 COUGAR 428-4V CJ, 428-4V SCJ, C2S, S2M, 2 REQD

1969-1970 COUGAR 428-4V CJ, 428-4V SCJ, C2S, S2M, 2 REQD

1969-1970 COUGAR ELIMINATOR, BOSS 302, C2S, S2M, 2 REQD

1970-1970 TORINO 429-4V CJ, S2M, 1 REQD

1970-1970 FALCON (FROM 1/1/70), 429-4V CJ, S2M, 1 REQD

1968-1969 TORINO 428-4V CJ, 428-4V SCJ, C2S, S2M, 2 REQD

1968-1969 FAIRLANE 428-4V CJ, 428-4V SCJ, C2S, S2M, 2 REQD

1970-1970 FAIRLANE 429-4V CJ, S2M, 1 REQD