[DavidG]

Graham,

Most of the originals that I have encountered were made entirely of brass with the part that fits inside the radiator hose cast to create a lip surrounding the threaded portion to affect a good leak proof seal. Some have steel hex nuts rather than brass.

The dimensions are as follows:
-- the base of the threaded portion that fits inside the radiator hose is 1 1/4" x 1 5/16" with the latter running front to back (I've several and all have that minor variation in their overall dimensions). The raised cross section at the top of the curve from the end view is 9/32". The radius is that of the inside of a upper radiator hose although it works equally well in both V8 and larger B outlet hoses. The 11/16-14 threaded portion is 3/4" and the overall height is 1 1/4". The recessed area above the threads is 3/32" and the inside of the opening at the top is slightly countersunk.

-- the outer portion measures 1 1/8" x 1 1/8". The hole in the center is 3/4". The thinnest cross section is 1/16" thick and the thickest cross section is 3/16"

-- the 11/16-14 hex nut is 1/4" thick and 31/32" across the flats although others have a nut 1 1/8" across the flats.

I'll try for better photos later today, but for the best quality it would be best if I sent them via email. For that, please p.m. me your address.