There are a couple of areas to check out on a salvage yard HEI. To work in a non-computerized application it MUST have a vacuum advance on it. The later models without vacuum will have a separate 4-connector pigtail that is intended to attach to the electronic spark control section of an onboard computer. Don't use that one! The older models will also have centrifugal advance weights and springs under the rotor assembly. The weight pivots have a habit of wearing out because nobody ever thinks about lubricating them. The advance assembly can also get rusty and sticky- - - -same reason. If you're interested in converting an HEI to extreme RPM capability for a race-only application, drop me a PM and I'll go into detail about how it's done. It probably wouldn't be necessary or wise to do that on a street machine.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!