DUI - flat gasket to block or o-ring?


Famous Member
Greetings Ford Six Fans,

I purchased my DUI many months ago for my old 200, but never had a chance to install it before I realized that the 200 needed to be rebuilt or replaced. Now I want to use the DUI with the new 250, and I'm ready to install it.

It's been so long since I purchased the DUI that I can't remember - does it use a flat gasket between the distributor body and the block? Or just an o-ring that seats into a groove? I can't find a gasket anywhere. I can't find a flat gasket at any auto parts web site, but I have seen O-rings. If it does require a flat gasket, I'll have to either get another one from Performance Distributors, or make one from gasket material.



Distributor Recurving.
Staff member
Approved Vendor
Supporter 2018
Bob, o'ring should be already on the housing of the distributor.
Before installation lube the housing area & o'ring area. Also put heavy oil or moly lube on the distributor gear to make sure no wear occurs on a dry start.


Well-known member
Supporter 2018
O ring.... the one that came with mine was too thick.... pick up another at ace hardware. 3,000 leak free moles so far.