Delco Remy distributor cap question
 

As I understand it, the correct 1970 Distributor cap will be embossed "Delco Remy Patent Pending R". Was 1970 the only year the "Patent Pending R" cap was used, or was this correct for 1969 too?

Does anyone have any idea of the current market price for these caps? They seem to be very rare. I'm surprised they are not reproduced yet.

69 should also be Patent Pending. And they are being reproduced. They are on ebay daily, and at Corvette parts sellers all over. Prices start around $50.00.

I thought all of the reproductions were missing the "R" (at least the ones I've seen)? Thanks... I'll look around.

Patent pending R was used on 69 also i might have one if you need it

I asked a question about this a while ago, and Chick came through with NCRS guidelines on Delco cap 'R' usage for pre-'70 MY at least. That thread is http://www.camaros.org/forum/index.php?topic=15310
However I didn't learn when the caps changed over from 'Patent Pending R' to having the patent number, so would be great to know that if anyone can clarify!

According to the NCRS guidelines, if it shows the patent number, it's considered a replacement?...Joe

The extracts of the NCRS guidelines posted in that CRG thread only cover '67 to '69 model years.
Not sure when the caps started to have the patent number on them, but as it appears to be some time in the early 70's, it follows that one of those caps on a 60's car would be judged a replacement.

Delco Remy distributor cap question
 

Delco-Remy caps without the R would be for 1968 and earlier usage. In 1969 GM came out with the R (resistor) designation. Caps D 308R ( black caps with aluminum contacts ) and D 309R (brown caps with copper contacts) and rotors D 409R (black with E on tip of contact) and various spark plugs with R designation, such as R43 or R43N, etc. Patent pending R were used until the patent office OK'd the R designation as being different from earlier caps, rotors, and spark plugs without the R. Then the patent numbers were imprinted on the caps once approved with R usage.These parts were then used on earlier applications once the earlier parts ran out of stock.

If you are still looking, here is a NOS D310 cap that has patent pending and the R on it.

https://www.ebay.com/itm/223454312472?

D310 looks just like a D308 but the towers that the plug wires go into are about 1/4 of an inch shorter. I doubt if anyone would be able to tell the difference once it was installed.

My reproduction cap has the R and then the patent number. I got it from AMES .They have a lot of good GM stuff. Chevy and Buick also.