Usually you buy a kit but I only need one and need conformation on the size of the plug that goes at the back of the block where the dist, spit plug is located. In lieu of my dial calipers my rough measurement seems like its 7/8 ???

 

cc,
I can check to be sure first thing in the morning. If you want send me an e-mail reminder

 

Size is 29/32 . Dorman part number 555-015