Topic: July 64 Dearborn - Distributor and Vacuum Advance

[tennesseejb]

About to put the original 4100 back on.  Prior owner had replaced with Holly, and cut the hard vacuum line. Ordered a new hard line, but in the process discovered the vacuum advance is bad, and am learning that finding one that has the screw in port is difficult (impossible?). I ordered one that take soft line for now and figure I'll keep looking for the correct one, but in the meantime, cleaned off the distributor to see what model it was, and it appears it may have originally marked C4AF and then over stamped with a "G".  It's also hard to make out the last letter, but I'm thinking it's a B and it looks like it may have been over stamped as well.  Hoping for more experienced eyes to confirm.

Thanks,
JB

[J_Speegle]

The last letter looks to me as a "B"  Little odd - may be the angle - look to the stamping. From this angle the stamp appears to have raised the leading (towards the rest of the enginering number) edge of the stamp

[markb0729]

You can try Tim O'Conner's website for the style vacuum advance you are looking for.  He retired but it may be worth a shot since the site is still listing parts for sale.
http://428cobrajetcars.com/new_parts

[tennesseejb]

Thanks Mark. I just looked and may do that. The one I pulled off though doesn?t seem to have markings. I?ll confirm in the morning but it may be a bad assumption but have assumed if the distributor is original maybe the vacuum advance is too. For a C4GF-12127-B do I need the Autolite vacuum advance or the B9AF unit he references for pre 65 distributors?

Appreciate the help!

Thanks,
JB

[markb0729]

I checked Bob Mannel's, Small Block Ford book and the C4GF-12127-B distributor with the 4FC date code would originally have come with a vacuum advance part number B9AF-12370-A.  If you aren't doing a concours restoration, the Motorcraft vacuum advance will work just fine.  In either case, you'll have to install the internals (spring and spacers) and hard line fitting from your old vacuum advance.  NPD sells a hardline fitting if you don't have one.  https://www.npdlink.com/search/products?search_terms=vacuum%2Badvance%2Bdiaphragm&top_parent=200001&year=1965

[tennesseejb]

Thanks again Mark.  I grabbed a copy of Bob Manuel?s book and appreciate your guidance there.  It?s so easy to post here, I tend to forget to look there. That being said, I already have the hard line in original steel.  I don?t currently have any goals of concours competition per se, but I am trying to preserve as much of the original look and function as possible and returning to a more original where possible. I think the B9AF actually saves me a little money on Tim O?Conners site, so I may go ahead and pull the trigger there.

I discovered something else interesting when looking at the book though? a predecessor for the C4GF-12127-B was the C4AF-12127-U which was used on the Comet/Cyclone.  When I look at my casting number, I could make an argument that it was originally the latter and the A was over-stamped with a G and the U was over stamped with a B when it was used on a Mustang.  That may explain why the B is harder to make out.

Anyway, back to reading? thanks again for the guidance!

JB

[tennesseejb]

Just wanted to close the loop here for anyone else that may be in a similar situation.

I did order a B9AF from Tim O?Conners website, and it did ship, so he is still fulfilling orders.  Should be here on Wednesday. The internals on mine look fine, so will swap those over and get them installed.

I couldn?t find the reference to B9AF in Bob Mannel?s book, but I find new things in there every time I look through it and I did find the 12378 under the crud on my existing unit.

Thanks,
JB

[markb0729]

The reference to the correct vacuum advance for your distributor can be found in Mannel's book, Appendix D - Distributors, pages D-10 and D-11