This is in my wife's 70 valiant.



(I assume it is not original as it has an electric choke and choke modulator hacked into the harness at the alternator)

I thought I was going to be able to use one of the pile of tstats I got on closeout from rockauto.

I noticed recently that is attached by 2-bolts (v.s. 1 like my van's.)

That's a '73 manifold. Choke thermostat compatibility is '73-up. Any '73 or newer choke thermostat (1bbl or 2bbl) will fit directly on this manifold. The only original choke thermostats that will work with this manifold and a '73 or earlier 1bbl carburetor are the '73 choke thermostats.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks.

Well I think the carb is newer than '73 (it has a purge canister hookup).

Since the choke works, I'll leave it alone until I pull the manifold for rust removal/paint/good gaskets.

I was going to change it when I rebuilt the carb (for no reason other than it is rusty)

Hopefully one of the t'stats I have will fit it (looks like the real difference is that the hole on the pocket closer to the carb is threaded on the Valiant, and not on the van. I don't see that affecting fitment.)

On another note, the throttle shaft on the aft end is wet and smells like gasoline.

I don't know if I should get it re-bushed, or start looking for a different core.

First year for that was '73.
Carb-side hole threaded: Choke thermostat held to manifold by two bolts. Carb-side hole unthreaded: Choke thermostat held to manifold by one bolt and one hook.
Carb's past due for throttle shaft rebushing or replacement. Pretty sure I have at least one new or as-new carburetor with appropriate hookups for a '70.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Right, which is why I think it is newer than 73. The only way that it isn't is if it happens to be specifically a 73, which the odds are against (unless the manifold and carb were pulled from the same donor for some reason, which tips the odds back in favor of it being a 73.)
Yes. It seems that a 2-bolt t'stat would require threading of the unthreaded hole on a 1 bolt manifold, but the 1-bolt t'stat would work on a 2-bolt manifold unmodified. (I found 'stock' t'stats on ebay for specifically 70, 71, 72 & 73 that were 1 bolt, 1 hook).
I might be consider that option. Thanks.

I have to figure out how to address choke options, and if I should maybe get a different year manifold. That may steer the choice of carb year. (and if I want to retrofit a purge canister).

Is it a Holley 1920? If so, it's a '73 (first year for EGR and purge port, last year for 1920), which would go with that '73-only choke thermostat you're showing. So I'm putting my bet on the carb being a '73 1920.
Correct.
Nope. Incorrectly identified or described. All pre-'74 choke thermostats are 2-bolt, and the '70-'72 items are the tall type with external adjustment locknut meant to sit atop the stamped sheetmetal cup that fits in the open-hole choke stove on the '70-'72 exhaust manifold.
...why would you need a different-year manifold? Choke options are easiest with this what you have; you can use a stock electric-assist or plain '73 choke thermostat with any pre-'74 1bbl carb, you can use a stock '74-up 1bbl choke thermostat with any '74-up 1bbl carb, you can use a stock '77-up 2bbl choke thermostat if you go Super Six, or you can use an appropriate Electric choke kit depending on your carburetor selection.
Not hard, see here and here, though if you do add a charcoal can that will constrain your carburetor options.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I don't know. Being ignorant of the carb/choke/manifold interchangeability I didn't know if something else gave me more options.

Didn't know 73 was last year for 1920.

If I can successfully rebuild/rebush the 73 1920, and can make use of new chokes I already have (for next replacement, but also spares/future replacement), and the exhaust manifold is not cracked or anything, then I should be able to do the canister too.

I guess the whole intake/exhaust/carb/t'stat came from one donor.

I wonder what went wrong with the original (all of those parts are in way worse condition than the rest of the car, which has less 40k on it.)

My guess: Previous owner frustration with the '70 choke system. New gaskets are NLA for the choke cup, and it's almost impossible to seal them up without the correct gasket.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Have you confirmed the year of the engine? It's not inconceivable that a previous owner killed the engine & had a complete-used '73 unit put in.

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63 Valiant Wagon
225 - 4 bbl