What is the difference between a 2843992 and a 2806974 exhaust manifold? Is it just the clock of the flange? Is the angle the same? I have a 2843992 on the 67 GTX and wonder if I get down pipes for a 69 GTX or
http://www.accurateltd.com/1967-B-Body-440-Engine-Complete-System_p_208.html
The 974 casting exhaust manifold is a one year only (1967) “B” body application. No other 440 left exhaust pipe will fit unless it is for a 1967 application. In 1967 h- pipes were installed on 1967 440 B body performance Dodge and Plymouth models. The 992 casting were for 1968 and 1969 hp models and is actually a better manifold as it is further away from the starter
and other parts. The same configuration was used up to 1974 with minor accessory and ribbing changes. Hope this helps.