I've searched many threads but cannot seem to find an answer.

I have a SBC 400 with Vortec heads, 9.1 compression, Comp XE284H cam, a MSD ignition with a Vac. advance dist. vac. adv. is hooked up to manifold vac.

Right now I have timing set at 10* base and 31* total. I've heard that Vortecs like less timing then most GM heads. Problem I am having is at idle. I would like to get the idle vacuum up as high as possible. Right now it is so low that sometimes it drops low enough that it won't pull the vac adv. then my RPM drops. This really sucks when you try to back into a spot at a car show and you have no brakes :D

Will bumping my base timing help with the low vacuum?

Is there an adjustable vac. can available for MSD Pro billet dist?

Another problem I have is it gets rather warm at idle, is that timing related?

Is the vacum advance hooked up to manifold vacuum or ported vaccum? Manifold may help. Vortecs seem to like the 32-34 range of total timming, so you should be able to bump it up a little.

Something else, that cam is huge for that little of compression. You could probably get away with 10.5:1 and still be fine on pump gas.

Steve

Put the 18* degree bushings in the distributor (it should have came with them), then bump up the initial timing to 14-16* initial. It will help you vacuum a bunch, and make it run better too.

Yes, it is using manifold vacuum. I'll bump it up and change the bushing and see what happens.