C3 Frame Cushion & Cushion Support Bolt Finish

[Gregory G.]

The frame cushions are die cast metal.Are they unpainted?
Are the bolts that attach the cushions to frame supports, also unpainted or are they black to match the frame color?

Greg

[Joe L.]

Re: C3 Frame Cushion & Cushion Support Bolt Finish

Greg-----

You didn't say what year C3 that you are talking about. It makes a difference. However, although you used the term "cushions", you also used the term "die cast metal". So, I'm going to assume that you're talking about a 68-72. 68-72 Corvettes used an aluminum mount as opposed to the rubber/steel mount used earlier and later. The aluminum "puck" was unpainted. I don't know if it was cast, or not. The bolts were black phosphate-finished, as I recall.

[Gregory G.]

Re: C3 Frame Cushion & Cushion Support Bolt Finish

Joe,

It is a 1970.
Also are the large flat washers black phosphate as well?
In the back wheel well area the pop rivots in the upper portion are they a natural finish or painted black?

Greg

[Joe L.]

Re: C3 Frame Cushion & Cushion Support Bolt Finish

greg-----

I don't recall what the washers were finished with. I don't know of any pop rivets that were ever originally used in the rear wheel well area. However, there were other rivets and I think that those were covered in the blackout and/or wheel well "undercoating" operation.

[Chuck S.]

Re: C3 Frame Cushion & Cushion Support Bolt Finish

I concur with Joe on all points except the body mount bolts...on my late 70, the body mount bolts were clear zinc.

The large body bolt washers are black phosphate, the flat washers on the No. 1 body bolt are black phosphate, and I show the nuts on the No. 1 bolt as dark gray phosphate which could be either black or dark gray.

I doubt the aluminum "pucks" were cast; I think they were machined out of discs cut from aluminum bar extruded to desired diameter. When I cleaned mine up, I could still see what appeared to be longitudinal striations from the extrusion process on the disc edges.

I found all pop rivets in the the rear area to be natural aluminum. In fact, I can't think of any pop rivets on the 70 that are not natural finish, but the mind is fading fast. I think the rivets you are refering to attach the shoulder belt anchor...as Joe says, inside the wheel well, they will be black from blackout and undercoating.

[Gregory G.]

Re: C3 Frame Cushion & Cushion Support Bolt Finish

Joe and Chuck,

Also in the rear wheel well area the square nut that holds the shoulder harness assembly and the backing plate that holds the chrome bar in place for the T Top straps are they also unpainted,natural finish.

Greg

[Chuck S.]

Re: C3 Frame Cushion & Cushion Support Bolt Finish

I have not removed the undercoating and blackout from the shoulder belt anchor plate. I think it would be crazy to do so, but...if you already have... : Based on my experience, I would guess the anchor plate was originally dip-painted in GM's black semigloss primer. It would have been too risky to leave it natural because of corrosion, and it's too large for typical black phosphate parts.

Other small underbody tapping plates, like those that attach the chrome loops for the T-top straps, were originally black phosphate finished IN MY OPINION...others say they were painted (I think the TIM&JG used to say painted), but my experience with my car says otherwise.

[Gregory G.]

Re: C3 Frame Cushion & Cushion Support Bolt Finish

Chuck,

In the front wheel well area are the head bolts painted black or are they a natural finish?

Greg

[Chuck S.]

Re: C3 Frame Cushion & Cushion Support Bolt Finish

Assuming you mean bolt heads, none are natural...without researching every bolt in the front wheel well, my memory says they should all be black phosphate finished. Very probable that they were also painted black during black-out, but not likely they will have any undercoating on them. On C3s, the AIM shows modest undercoating only on the back of the wheelwell.