I am thinking of using on in my 383 that i am building but a may use a isky

Schneider is all we run now.

We have a local racer/speed shop owner/Schneider dealer here in town that has been using them since the 60's. (Lanier Henry, 55 Chevy blown BBC)

After wiping a "Major name brand" for the first time in my life, he set us up with custom BBC grind for street driven high altitude use. He says the aggressive lobe taper helps them survive the break-in process.

Since then, I have installed quite a few, and never had any problems at all.

They are great folks to work with, and have speedy service too, they had ours to us in about 10 days.

I recommend Schneider highly.