Yes and No. The 24 valve washers are a bit smaller OD than some 12 valve washers I have seen. I haven't checked if these bigger 12 valve washers will fit in the wells in the 24 valve head--they probably will. The 24 valve washers are about 0. 060" thick (1. 5 mm)--same as the 94-98 12 valves (except 215 hp whick takes 0. 5 mm thick washers or about 0. 020").
[This message has been edited by Joseph Donnelly (edited 02-18-2001). ]