Distributor codes

[North Central Ohio]

I haven't asked any questions since I've been on this site,cause of cash flow situations,til now.lol. I have an '86 C10- 305 -700r4 that I want a period correct distributor for. Its an esc distributor and from what I've gathered, Chevy distributors have codes on their shalves to determine what vehicle (yr,make,etc..) they were made for. My question is, what code do i need to look for for my truck?

[VileZambonie]

What are shalves? You can purchase remanufactured application specific ESC distributor. No special coding is required.

[North Central Ohio]

I must have the terminology/English wrong. When I say "shalves",I mean the shaft that a distributor has that goes from the bottom of the distributor cap to the inside of the engine w gears on the bottom. I might have got wrong info also,but the info I saw said there's a code on the shaft,or collar,that tells you what vehicle application the distributor is for...kinda like the 7-8 digit carburetor code,but for distributors. There's a junkyard i want to check,but I want to know ahead of time what to ask for and not have to say,"I'm not exactly sure what I want/need." I'm kinda anal when it comes to certain things and this is one of them.lol. id rather go the junkyard route since theyd probably have a more "period correct" supply of parts for my truck.