This will be an interesting thread for you to read if you have not already seen it.
It Is 24 pages long lots of info.
Link:
http://67-72chevytrucks.com/vboard/s...f+spid&page=24
About Your SPID.
4G50AC -Heavy Duty rear spring
4pv3fa? (maybe) is front tire info
4622AH -Gold Vinyl Trim
1Q(C-or G)IFC - probably the (municipal color)
4K76DN - amp of Delco alternator (as Steve mentioned)
4PV5KA- Maybe something about rear tire or spare tire?
Here's a few pics from the SPID thread.
1st one has the same as yours HD Rear Spr.
2nd and 3rd just start with 4 like your's.
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Below Is A Link If You Want To get One Reproduced
Jeff does a Great job.
Link:
http://outintheshop.com/2.html
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