Looked back to the 1979 DC Cat. and the Tunnel Ram P3690233 and the top P3690234. This top is not as short as my top on the blower intake manifold. The manifold base states it is a Weiand magnesium Tunnel Ram.under all this it states I.R. mounting plates for use without plenum allows direct mounting of Carburation. and the part number P3571054.