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Re: up and down play in dist shaft... (corvette90)
as topic says, is it normal, to have about .050 up and down play in the dist shaft??
Yes. That is normal. But that doesn't mean it can't be fixed. My Helms manual shows the disassembly of the distributor, but gives no specs for clearences, including end play. *I* feel .006 - .010 is plenty. When that shaft moves up and down, the gear that is pinned to it moves up and down, also. The teeth on that gear are helical. That means when the shaft moves, the gear turns and changes the ignition timing. There are distributor shim kits available in the aftermarket. Mr. Gasket sells one, I think. I don't care how much that shim kit costs (should be under $10.00), or how much trouble you have installing it, it will NOT increase your horsepower. If you are a bracket racer, however, it may do a little something for your consistancy. Good luck, and...
Re: up and down play in dist shaft... (corvette90)
Yes its is perfectly normal. I have seen as much as .090 in the HEI distributors and about the same in the old points distributors. I have been rebuilding some older GM points distributors and modifying them with the Pertronix electronic ignition conversion kits. When those kits are installed I have to shim the end play out of the shaft for the kits to work properly.