EFI to Carb Distributor Shaft length question...

MikeR351w

Founding Member
Oct 8, 2001
207
0
16
Wisconsin
www.geocities.com
Hello, I am building a Factory 5 Cobra with an 89 GT mustang engine. To make it more period correct, I am going to a carb set up. I have it almost finished and just bought a Distributor for a 85 Mustang GT 5 speed. The old TFI dizzy was longer and this one is shorter. I checked with a gauge and it appears as though with the 85 distributor, I will only make about .170 of shaft contact. Should I get a longer oil shaft and if so, please tell me the part #! I cannot find anything on the subject. Thanks!
 
  • Sponsors(?)


Steel1

Mustang Master
Aug 18, 2017
1,129
514
143
51
Connecticut
Just thinking out loud, but is the part # for an 85 oil pump shaft different vs 89 302 , if so
could be a different length.
 

7991LXnSHO

Now I want a 10 year badge
10 Year Member
Sep 1, 2010
3,139
590
164
Kearney, NE
So do you think you got shafted? :doh:
Usually it is the distributor gear we need to make sure is right for the cam.
I am following as I thought 302 distributors were all the same shaft length. If the new one had been switched with a 351, it would be longer for the taller desk height. So what is the length from the stop shoulder to the end of the gear on each?
 

CarMichael Angelo

clearly, I’ve got something going on in that hole
15 Year Member
Nov 29, 1999
9,309
7,186
234
62
Birmingham, al
m.imdb.com
They have a different shaft diameter, not length i believe, ( something like .531 vs .468) The gears are different between a roller and non-roller spec’d distributor.
 

MikeR351w

Founding Member
Oct 8, 2001
207
0
16
Wisconsin
www.geocities.com

So do you think you got shafted? :doh:
Usually it is the distributor gear we need to make sure is right for the cam.
I am following as I thought 302 distributors were all the same shaft length. If the new one had been switched with a 351, it would be longer for the taller desk height. So what is the length from the stop shoulder to the end of the gear on each?


the difference is.500 in length. I did not know they are not the same diameter
 

Steel1

Mustang Master
Aug 18, 2017
1,129
514
143
51
Connecticut
351w efi distributor is longer ,I would imagine carb is as well.
Not sure if it would work in your application.
I actually had to cut mine down about 1/4" when I built my 393w.
 

MikeR351w

Founding Member
Oct 8, 2001
207
0
16
Wisconsin
www.geocities.com
I think I biffed! I tried to prime the engine by cranking it over. i assumed the shaft was short and its not. I changed out the oil filter and oil beforehand, and used assembly oil on the lifters and rockers. I am thinking I had an air bubble while cranking. i used a drill to prime and instant oil pressure!
 

MikeR351w

Founding Member
Oct 8, 2001
207
0
16
Wisconsin
www.geocities.com
cheapest and easiest to set up
 

Attachments

  • 369FB815-2CA2-402A-BC7B-6448AAEBE458.jpeg
    369FB815-2CA2-402A-BC7B-6448AAEBE458.jpeg
    934.3 KB · Views: 27

7991LXnSHO

Now I want a 10 year badge
10 Year Member
Sep 1, 2010
3,139
590
164
Kearney, NE
I have been thinking about this and have three ideas, and the second one has the best probability of success.
1. Maybe there is a truck or some other car that had the old style ignition with the EFI distributor.
2. The EFI to Carb conversions call for a 1985 distributor. I still wonder if the right part was in the box.
I think @jrichker has posted how to use a duraspark 2 or HEI 4 terminal module instead of the computer.
Start at about #21.

This looks super easy. I wonder if the EFI distributor will trigger a HEI module? If so, problem solved.
3. See if MSD has the one for your conversion.
 
Last edited: