1970 350 HP distributor fitment after rebuild

[Stephen B.]

I recently rebuilt the distributor on my '70 350 HP car. After the rebuild, the distance from the vacuum advance plate and the cam plate for the mechanical advance cam has evidently decreased in size after I put it back together. I cannot fit my Pertronix ignition in the distributor now. I've double checked how I put the distributor together, and the mechanical advance cam fits on the vacuum advance plate as before. Am I missing something here? Attached is a picture.

Thanks in advance.1970 Distributor measured from Vacuum Plate to Mech Adv Cam.jpg

[Mark E.]

Re: 1970 350 HP distributor fitment after rebuild

I have a loose distributor from a '70, so I made the same measurement... 1 1/8".
It looks like your photo shows 7/8"... about 1/4" less.

Are you sure you're measuring from the top of the breaker plate (aka vacuum advance plate)- and not the top of the ignition points base? I measured from the top of the breaker plate.

If you did lose 1/4", I'm at a loss why. Do the main shaft and tach cross gear mesh and turn freely? It seems if the shaft was too low, these would bind.

[Mark E.]

Re: 1970 350 HP distributor fitment after rebuild

I just looked at the photo in your other thread about the distributor football. It looks like the weights are overlapping. They should sit flat on their base. Maybe once you straighten out that issue, you'll gain the clearance you need.

[Owen L.]

Re: 1970 350 HP distributor fitment after rebuild

Are you sure the advance plate is fully pressed down? It looks a tad high to me -- as in, did you reinstall the C-retainer clip after slipping on the plate? Did you use any shims between the cam gear and the housing -- could that be too tight?

[Larry M.]

Re: 1970 350 HP distributor fitment after rebuild

Is your cam gear (lower distributor gear) installed correctly?? Could it be upside down??

Larry