Not.
Absolutely NOT.
The same valley pans were used on ALL engines of that particular model year, whether it was a lowly 2-barrel engine, a 4-barrel engine or a Tri-Power engine.
Yes, all Tri-Power valley pans had the PCV port located at the rear of the pan. Tri-Power was offered from 1957 through 1966, consequently ALL engines built during those years had the PCV in the rear
no matter what carburetor setup was ordered.
Technically you could say that any pan with a rear PCV location is a Tri-Power pan. But it's also technically a 2-barrel pan or a 4-barrel pan as well.
The pans with a rear PCV location are really nothing special, just an older style harkening back to the days when there were no PCV valves in use. Road draft tubes were used back then, up until 1963 if I'm not mistaken.
Road draft tube on a 1959 389.
The last year that valley pans used the rear PCV location was 1967, and as we know Tri-Power was no longer available for 1967 models.
Here's a 1964 valley pan that I personally pulled from a 2-barrel 326 Le Mans in the boneyard.
That 2-barrel 326 pan just so happens to fit perfectly under the 1964 Tri-Power intake on this 421 HO. Because it's not a 2-barrel pan or a 4-barrel pan or a Tri-Power pan specifically, it's simply a 1964 valley pan.
Another example, a 1959 2-barrel 389.
Fancy that, a 1959 Tri-Power intake fits perfectly.
Here's a 1972 valley pan with the front PCV location, 1968 - 1972 pans all looked like this one. I tried using a 1969 pan at one time with a 1966 Tri-Power intake and it wouldn't sit down on the heads, due to the forward one of the two 'pyramids' interfering with the bottom of the intake. Of course the 1968 and later pans were never intended for use with Tri-Power.
