Aluminum AST cap dimensions
 

I need to find a replacement cap for my Alum AST, and it would help if I knew what the dimensions were.

This is the only thread I could find on the subject:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/ast-cap-rebuild-flooding-questions-long-220112/

We need to know which AST your running. IIRC there are only two sizes, the domestic type which are the large ones, and the import type (like the factory original) some aftermarket AST's can have either, the aftermarket AST's that have the lever on them are typically the domestic (large one) but I'm sure there are exceptions to this rule (which someone will point out) just for example the Pettit after market AST runs the large cap, the Tri-point Eng. aftermarket AST runs the factory style. All you have to do is determine the manufacturer of your AST.