choke for Holley 1 bbl

Yep, if you've got the open-rear-wall choke pocket, it's a '73-up exhaust manifold. The earlier choke thermostat will bolt to it, but won't work right; the open wall will cause it to heat up too slowly and cool down too fast; you'll waste a lot of gasoline that way. Most of the choke thermostats for the '73-up exhaust manifold are the electrically heated type, but not all of them are. Here is a '73 non-heated choke thermostat. I don't like these '73-up (heated or non) because they are not adjustable. If the factory calibration doesn't happen to match what you need, or if you change the carb flange gasket to a thicker one to reduce percolation, you're outta luck. Better to install one of the fully adjustable Electric choke kits that does not know or care whether the manifold pocket has a cut-out wall. Note that '73 is a one-year-only setup with respect to the pushrod that runs from the choke thermostat up to the carburetor. The top of the pushrod turns right to point forward in '73 (and all previous years); it turns left to point rearward in '74 (and all subsequent years). If you are using a '74-up 1bbl carburetor (Holley 1945), you have to use the points-rearward-at-top type of choke pushrod. Otherwise, the points-forward-at-top.


The photo Cudamark posted shows a '60-'61, a '62-'65, or a '66-'69 Carter choke thermostat on the left (can't tell which of these three year ranges it is without having all three in hand; rods are different), and a '70-'72 Holley choke thermostat on the right. '70-'72 exhaust manifolds have an open-hole "stove" in place of the cast-in pocket; a stainless steel cup sandwiches a gasket to the stove hole, and the choke thermostat sits atop the cup. These '70-'72 choke thermostats do not work correctly in other-year exhaust manifolds, and the reverse is also true. There is no need to worry about Holley vs. Carter; they are fully interchangeable no matter which brand of carburetor you have.