Original 67 BB Brass Radiator Drain Plug

[Michael G.]

I am searching for an original factory correct 67 BB radiator drain plug for my early production coupe, but don't know exactly what it looks like.

According to the 67 AIM, the part number is 444819.

I understand that this part is supposed to be brass since it is intended to be inserted into a copper-brass radiator.

I think that it is a 1/4" NPT part with a maximum thread diameter of just over 1/2" with a hex head.

I would appreciate it if anyone who has a correct brass drain plug would please provide its specifications, to include thickness and diameter of the head; length; and head marks, if any. A photo or two would be very helpful, as well.

Thanks, Michael Gebhardt

[David B.]

Re: Original 67 BB Brass Radiator Drain Plug

Mike,
If your part number 444819 is correct the filler and drain plug you refer to according to GM Engineering standards is a Steel, cadmium or zinc
1/4 - 18 plug.

[Michael G.]

Re: Original 67 BB Brass Radiator Drain Plug

David, thanks for looking into this issue for me. 444819 is the part number in the 67 AIM as shown in UPC L36, Sheet A5. However, the latest (6th Edition) of the 67 Judging Guide says on page 177, for BB cars, "Initially in production, a brass hex-headed plug was used in lieu of a petcock. In January of 1967, a revision to use a brass petcock was made."

I understand that 444620 is an identical part, but made of brass. Could you kindly check the specs of that part in the GM Engineering standards?

Thanks, Michael

[Paul O.]

Re: Original 67 BB Brass Radiator Drain Plug

Mike this what it would look like.

[Michael G.]

Re: Original 67 BB Brass Radiator Drain Plug

Paul, thanks very much for the photo. Taking measurements on my screen and adjusting the scale, it looks like the head is about 9/16" in diameter, and the thickness of the head is about 1/8", maybe a little more. Really appreciate your help. Michael

[Gary B.]

Re: Original 67 BB Brass Radiator Drain Plug

Eaton or Weatherhead 3152x4 is currently available in most auto parts stores. The elbow that Paul shows is 6400x4. I buy both regularly at my old-time auto-parts store. You can buy them online at many places also.
Gary

[Michael G.]

Re: Original 67 BB Brass Radiator Drain Plug

Good to know that, Gary. Thanks, Michael

[David B.]

Re: Original 67 BB Brass Radiator Drain Plug

Part # 444620 is Brass Plain finish pipe Plug --
A) Dryseal thread (NPTF) 1/4 - 18
B) Shoulder length .56
Full thread length .46
C) Head width max. .565
min. .551
D) Head thickness max. .194
min. .181
E) Recess Diameter max. .25
F) Wall Thickness min. .12

[Michael G.]

Re: Original 67 BB Brass Radiator Drain Plug

David, just what I needed to know. Thanks for staying up late to provide this info for me. Michael

[David B.]

Re: Original 67 BB Brass Radiator Drain Plug

Mike,
I don't stay up late. The dogs got me up an hour earlier to go outside and chase rabbits, raccoons, skunks and whatever else they do.