'If you mean?' You have either OEM Part #32580-64 Base [circuit breaker] '64 & '65.
Or later '66+ up, these are auto-advance with totally different internals. Even the base is fastened down differently. The auto-a's have 2 studs come up thru the base cap, whereas Part #32579-49 "HAS THE NOTCH" you describe, but is held down by a retainer clip. W/very different timer shaft housing.
Even if you get the notch dimensions, you would have to place it very correctly & remove the advance weights, & etc..
IMHO, you would NOT get the satisfactory results, anyway.
If that's what you mean???
If you have the Correct "Timer Shaft Housing" I'd just get the right base.
[This message has been edited by BillyW (edited 30 October 2004).]