Early and Late Dizzy Question

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Mar 27, 2009
My '83 2F large cap dizzy is in poor shape, which I eventually plan to send to JimC to recurve and rebuild, but until then I wanted to use my '68 F vac advance dizzy. I'm running all of my 68 accessories and D40. I thought I understood @FJ40Jim post explaining on @wngrog 's build thread that it was possible to use.

Remove temp sender & holder from the 68 engine & thread into 81 engine to work with 68 gage.

To keep ignition simple, use the vac advance 1968 dissy & clamp. If changing to a 2F dissy, be sure to use the thinner 2F clamp so it doesn't hold the dissy up off the block.

Here are pics of my two dizzys. Is my supposedly 68 dizzy correct? It won't fit all the way in as it is riding on the gear's collar.
Well I got past the O ring. Is it supposed to rest on this shoulder? I have the clamp off while i was fitting it in. Since the clamp goes on the shoulder I didn't think it mattered until I actually mount.
Yes, the early dissy rides the gear on top of the oil pump. It will usually sit slightly proud of the block as shown in your pic.

Note how the gear is flipped between your 2 dissy. That is how to tell if the dissy will register on the block surface or on the oil pump.

Also of note:the early points dissy in your pic is a vacuum retard type.
Also of note:the early points dissy in your pic is a vacuum retard type.

Great point. He would be screaming crazy like I was the one time I used one and did not know such an animal existed
Well that is good information as I dod not know the difference. So, I'm guessing this one from a 75 2F is a vac advance since the vacuum module would be pulling in the counter clockwise direction? And, would this work for me considering the above?
Thanks Rocker. Looks like I need to see JimC sooner than later...my other appears to be a retard too.
The 61020 is a 1975 USA spec vac retard dissy. It is a vac advance body casting, but has a weird vac canister that pushes instead of pulling, to create the 'retard when vac is applied' effect.
Thanks @FJ40Jim . Can I add to your workload to get my large cap dissy rebuilt and recurved?

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