Quote Originally Posted by rspears View Post
Gary,
Is this for the 383 SBC that you're planning to build for the Astro Van, which I think you've said will be used primarily for highway with towing capability for your vendor trailer(s); or is this another engine or a general question? I can't help with the dual roller chain question, but I cannot see from a mechanical design standpoint how it could make a difference (other than clearance, as pointed out) so I hope any answer saying it's not to be done includes the "why".

On the stock timing set, wouldn't any "built in" advance be dealt with when you degree the cam to set it where you need it to be for your specific situation? You'll discover any factory "offset" when you run the degree wheel, won't you? Maybe I don't understand the problem?
It's a general question Roger.Not for the 383/Astro.

The GM gear set statement is for many of the users on here that honestly don't degree their cams. I would venture a guess there are a large percentage of people in that group.