Fasteners for Access Plate - rear inner fender

[Ed S.]

Can someone describe the correct fastener and its finish for the 4 fasteners that secure the access plate that covers the body mounting bolt inside the rear wheel well for a 1964 Corvette.

The judging guide does not discuss the fasteners - just says the plate is installed after sound deadening "stuff" is sprayed inside the wheel well.

The AIM says this fastener is a "3848320 Screw Assembly" and, from the drawing it looks like a flat tip screw.

There are 4 threads in this forum on the panel and fasteners. In two threads respected members state the fasteners are zinc, in the two other threads (different) respected members say the are black phosphorous. No one describes the fastener (hex, phillips, whatever....).

Some of the more popular Corvette parts vendors carry the fasteners. One vendor shows the fasteners to be a Phillips head screw that is black ph; the other vendor shows a zinc finish hex head screw with accompanying star washer.

A thread in this forum regarding the fastener for a 67 horn grounding wire says the 67 AIM specifies a 3848320 screw assembly - and the member attached a photo of it, it is a zinc finish hex head with star washer.

After all that - please describe the fastener and its finish for the rear access panel for a 64 Corvette. Zinc / hex seems to satisfy the description of the part # but those 4 zinc heads would stick out like a sore thumb against the panel cover and wheel well and it just doesn't sound right.

Thank you

[Edward J.]

Re: Fasteners for Access Plate - rear inner fender

Ed, my 63 fasteners are a 5/16ths head size, indented head , with star washers attached which I believe to be originals. the head marks may vary, but mine have anchor head marks.

[Ed S.]

Re: Fasteners for Access Plate - rear inner fender

Ed,

Thanks - that is a very good data point regarding the shape or configuration of the fastener. A follow up question, are your fasteners zinc or black phosphorous?

[Edward J.]

Re: Fasteners for Access Plate - rear inner fender

Ed, the fastners are old and have been cleaned, I would say they were Blk. Phosphate., I think the repros are Zinc.

[Jim S.]

Re: Fasteners for Access Plate - rear inner fender

I can't answer your question on 63 & 64 cars, FWIW the 65 JG states the access doors are secured with cad or zinc recessed hex head bolts.

[Gene M.]

Re: Fasteners for Access Plate - rear inner fender

I can't answer your question on 63 & 64 cars, FWIW the 65 JG states the access doors are secured with cad or zinc recessed hex head bolts.

The zinc is a very common '65 production line finished used but the cad is very unlikely. Mostly the government was the only user of cad once it was published of it's toxicity. I would not be surprised if GM did not put a finish on some of the smaller screws at all.