How do I know what HEI distributor to get?

[joeydurango]

I'm in the process of tuning up my '72 K10. It is a 350 w/ HEI, but it isn't the stock engine - it's some crate 350 from, I can only guess, the 80's or 90's. Still has the QJet, no crazy cam or anything, seems pretty stock-like.

I've been checking out the timing and neither the vac advance or the mechanical advance appear to be working. Tomorrow I'm going to pull the cap off and check out the condition of the springs and weights, but I suspect things are worn in there, and stock-ish distributors don't seem very expensive.

Reading up on things, it seems that some distributors were made specifically for certain engines, and sometimes not so much; looks like there are differing amounts of mechanical and vacuum advance available, total degrees of advance, etc. I figure there must be an HEI setup that is pretty much plug-and-play on a stock-type 350... but not sure. Anyone know, and if so, have a link to what works? Thanks!