Carburetor Question

The Autolites were all model 4100. There were 8 different numbers used for '65 289s. Did you have a PCV system? Automatic or manual transmission? We could maybe get it down to no more than 4 possible numbers.

Good carb if you can find one. As with a lot of things, they aren't making any new ones.

OK, since you said 3-speed I should know its a manual!

That means the '65 4100 numbers for a Mustang would probably have been:

C5ZF-C or C5ZF-E if you have a PCV system
C5ZF-J if you have a road draft tube

Those are all 1.08" venturi 4100. The 1.08 is prominently displayed on the side of the float bowls.

You can look for 1.08 4100 carbs on ebay. They are great carbs. If you use an Edelbrock Four barrel intake, there is a small issue of sealing the base of the carb to the manifold, easily. Remedied with a thin spacer plate. You do not want any vacuum leaks.

Last one I bought on eBay was about $250. I was very lucky to find a numbers matching. Mikes carbs has full rebuild kits for about $100.