On my 1968 XR7-G with an S code 390, I am having trouble getting the air cleaner to seal over the carburetor. I installed the same style carb that was original to the car (Holley 4150) and the air cleaner doesn’t clear the front float adjusting screw on the top of the carb. The base has a dimple to clear the float adjusting screw on the back of the carb, but not the front.
What am I doing wrong? Do I have the wrong air cleaner base?
The S code air cleaner base for '68 has a round vacuum operated air valve that opens on acceleration, bypassing the snorkel to let in more air to the filter. It is unique, only the 1968 S code Mustang / Cougar used this.
That lid has me confused too. It is the lid for a '69 Q code 428 or Boss 302 which is a smaller diameter housing than the '68 version. The '69 housing has a square pull off door on the side instead of the round one used in '68.
This one looks like the 1969 390 air cleaner. It is nearly the same as a 428CJ non ram air unit. and the 69 Boss 302 non ram air unit. Thew snorkel is the area of deference between the applications. This unit is also expensive, so it could net you a correct unit.
No, the '69 Boss and CJ cars used a Holley carb too, so it ought to fit just the same. The snorkel is different, and used a different S tube, so the S tube probably won’t fit properly.