differential pumkin color

[John R.]

i am building a ncrs 1958 vette. what is the color of the differential pumkin ??? black or unpainted??? thanks !!!

[Alan S.]

Re: differential pumkin color

Hi John,
Since you haven't had a reply from a straight axle person I took a look in Noland Adams' Tech Guide. In the 58-60 section the photos of the chassis on the production line show the rear axle housing and pumpkin painted black.
So, I'll vote 'black' and this post may get you some new views.
Regards,
Alan

[Tom P.]

Re: differential pumkin color

John,
I've already been down this road 2-3wks ago with ZERO difinitive responses.
Thus, I'm guessing that no one really knows!!!!!!!!!!!!!!!!
Here is what I've observed from 40+yrs of rebuilding the 55-64 style rears (56-62 for Vettes).
FOR SURE, the 55-56 and up through some time in mid-57 production, the inside AND outside of the rearend center cases were painted a red oxide color (as in red primer).
Then, apparently by sometime in mid-57 production the red oxide was no longer applied. From thereafter, black seems to be predominant on the OUTSIDE ONLY. AND, I don't know if the black was applied at the Detroit Gear and Axle plant (ALL Vette rears came from the DG&A plant only), OR, if the black was what got applied on the chassis line before body drop. The inside is raw cast iron with only inspection color splashes and a +/- number hand painted which related to the pinion shim thickness.
That's the best I can tell you. Again, as I mentioned, because of previous lack of replies, it appears there is little to no expertise on this issue. Consequently, if it were my car, I'd go with something as close as possible to the chassis black. You certainly can't go wrong with that, because that was applied to the fully assembled chassis prior to body drop. Therefore, exterior paint splash markings, inspection marks, etc, that were applied BEFORE the rearend assembly was shipped to the St. Louis plant would have been covered up by the application of chassis black------------of course, the amount of paint/inspection markings that got covered up was entirely dependant on how thoroughly the assembly line worker sprayed the chassis black! If he was hung over from the night before, or was getting a little behind on the chassis that were moving along the line, he may have only sprayed it with a lick and a promise.