I have a 1954 Pontiac and the front suspension has a 3/4-11 threaded rod for the upper control arm. I am looking for a 3/4" tap that has 11 threads per inch. Any ideas where this oddball size came from and who would have such a tap?
I can't truly answer the question of where this oddball size came from. I believe some companies come up with oddball taps so customers will have to come back to them for parts. However, there is a company called TAPCO in Rockford, Illinois that can make any tap you want. They are, of course, only one of many companies that manufacture taps to order. Dave Butcher
President
B Machine Products
Parkersburg, WV
What exactly is the rod used for? You sure it was original to the car and not a quick fix someone with a lathe built themselves?There are many companies in business that sell front end rebuild kits and one for a Chevy of same year may work.
Be sure of what you need b4 buying anything. I looked in a catalog from MSC and they list 11/16 -11 taps. Find a machinest and ask him to check you part. let me know.
Besure to check the treads with a thread gauge, as there is a 3/4"-10 taps out there also. I would think that it is really a 11/16"-11 or a 3/4"-10 not to say they don't but most auto companys in that time period just standard type threads for ease of avaiablity and cheap tooling. I just find it hard to think it's not a standard. Post back and let us all know what you've come up with. Tom