Well I milled the 1 3/8 hole for the dist in my manifold today, and milled flat the casting around the hole, took off about .015. When i set the manifolds next to each other I noticed that on the TPI manifold the boss the dist sits on is at an angle to the bottom of the manifold. I machined mine flat. It appears to be about a 15 degree angle. Has anyone else noticed this? Will it be a problem?

 

It won't be a problem at all. I don't fully understand why the TPI intake base has a angled distributer hole but compare any other SBC intake including the LG4 are all flat.
I didn't worry about it.

 

Thanks for clearing up the confusion.