Back when I had my motor built, I got a Summit HEI style distributor for it. I could never get it to fit and clear the water neck. I even tried the water necks with the flat spot for clearance. Nothing. So I stayed with the stock dizzy.

Now, the motor is going in an '88 F350, and there is no ignition system in the truck as the EFI computer and all wiring has been removed. I want the HEI style to avoid tracking down a Duraspark system and having all the extra wiring under there.

Are there any water necks or distributors that I have missed that will work? I'm running an Edelbrock Performer intake.

If I have to, I will make a water neck to fit.

*Edit*
This is for a 460

 

Well, you said you've already tried it, so I guess I may have a wasted post here, but I remember doing something like this YEARS ago by using one from a Ford van.
Try a Four Seasons 84998, an application for an early 80s Ford van with a 460. You may have to take a hand grinder and massage a little bit of the corner off your distributor and some material off of the thermostat housing. If it actually does fit, you'll obviously have to plug a few of the accessory holes with pipe plugs. Also use the thinnest paper gasket you can find.
I'd try to talk you out of the HEI distributor, but that's probably a hopeless case.

 

I have an HEI style distributer from Assualt Racing in my 460 with one of the flat spot water necks and it fits fine. I have the electrical plug facing the carb, not sure why yours doesn't fit.