Guys - I'm looking for an adjustable vacuum advance for David's 300 six to give us the ability to tune it while he's here for the GTG. But I'm striking out. Plenty of ones for the V8's, but I haven't found one for the 4.9L. Nothing at Amazon, Jegs, Summit, etc. Anyone know of one?

 

Can or dizzy ?

 

Can. I found a whole dizzy, but that's a bit expensive at $300.

 

Number Dummy had a list of compatible units in that thread.

 

Yes, but I think there are two problems with those #'s. First, he said the info comes from the "1964/72 Ford Truck Parts Catalog". That wouldn't be the DS-II dizzy. In fact, I'm pretty sure it would be a points dizzy as my 1972 F250 had points. I don't have any way of knowing if the points-style vacuum advance works on the DS-II, but I would have thought the after-market vendors would have touted that for their advances and they don't.

Second, those are Motorcraft vacuum advance units, and the original unit on David's truck isn't adjustable, so I'd assume the replacement wouldn't be.

Edit: I should have said THANKS!!!! I do appreciate it.

 

No worries. I dont know enough about it to be much help. Though either that thread or number himself might help.

 

ND will give me Motorcraft #'s. Obviously we don't want another of those advances since they apparently aren't adjustable, but the #'s might let me check to see if there is any V8 advance that will fit the six. I doubt it or those that make the vacuum advances would say theirs fit the six, but it is worth a try. Thanks.

 

Why would the Crane kit not fit the I-6 distributor?
AFAIKT the base plate, advance and pickup are the same.
Just the reluctor, shaft and cap are different.

 

I don't know the answer to that. Just that Crane doesn't say it will fit. They only list the V8's. If no other option presents itself I'll order a Crane from Amazon and if it doesn't fit either return it or use it on Rusty.

 

I don't have a 300 dizzy to compare, but if the baseplate and housing diameter are the same I don't see how it could not fit.
I know that points distributors have a different P/N for the advance unit because the arm has more stuff to clear.

 

I don't have a six dizzy to compare either. But it makes sense that Ford would have made everything identical if they could.

I had hoped to compare part numbers for 6 vs V8 advances to see if they would swap, but that's an area of the parts catalog that is difficult for me to traverse. You apparently have to start in the Calibration Code section and find a code for each engine that is in a similar vehicle. Then get the dizzy number from there and go to the dizzy section and get the vacuum advance number. But, as I'm sure you know, there are so many variables in doing so that you come away dizzy.

 

what do you mean, can or dizzy ?

 

Can= vacuum advance canister
Dizzy=distributor

 

Aye.

Using slang terms keeps Google from identifying threads (text) where good information may be found.

 

Well, first of all, "thanks, Gary" for all you are trying to do to make this happen!

I have posted a thread @ Fordsix Performance since there are two guys on there who specialize in recurving distributors. Hopefully, I will get an answer, there.

I also posted in the six cylinder section of our forum.

Lastly, I looked on Rock Auto and arbitrarily selected the year 1982. I selected F150 with the following engines and compared what was offered: 4.9L, 302 and 351. None of the canisters overlapped. Each was specific for its engine [not surprising, I guess, since each engine has different operating ranges, etc.].

What I did find interesting is that 2 canisters for the 4.9L and 1 for the 351 indicated that "Advance starts @ 5" Hg". If you recall in a recent thread where I was discussing that I had measured the vacuum of the sole carburetor vacuum port [using 1970 Carter YF] and it was 5" Hg @ idle, but never exceeded 10-11". It was pointed out by Franklin2 that this was most likely venturi vacuum. Just food for thought...