72 THM 350 mount and bolt thread?
 

When reinstalling a crate 350 engine, I noticed my transmission mount had 2 different bolts to attach to the cross member. Since I had the Transmission rebuilt last year, I was surprised that the mount would use 2 different bolts. Or, either they lost a bolt or my truck had 2 different bolts when I brought it to them.

When I reinstalled the (different bolts to the mount, one of them wouldn't tighten up, it just turned and obviously it stripped.

I went to buy a new mount from NAPA, and said I wanted to match up 2 bolts too, and the guy said that might be difficult to match those "odd" threads.

What is the correct bolts for the mount to cross member? I couldn't get any SAE or metric to thread in easily. Maybe a course 3/8 would work, but it didn't thread in by hand. I don't want to strip out a new mount with the wrong bolts.

Anyone else run into this?

Re: 72 THM 350 mount and bolt thread?
 

I bought 2 bolts today that seem to be the right thread, 3/8 13 (or 14, I don't remember) and they seem to do the trick. Apparently the mount (Korea) has at best, rough threads cut in the mount.

Re: 72 THM 350 mount and bolt thread?
 

The bolts that fasten the trans mount to the trans cross member are 7/16 14

Re: 72 THM 350 mount and bolt thread?
 

7/16-14 ...Read this, ;) https://www.jalopyjournal.com/forum/...t-size.243192/

Re: 72 THM 350 mount and bolt thread?
 

Yep, I got the wrong bolts. Actually, I didn't buy them. 7/16 14 is right, but they seemed tight and not wanting to thread in. I ran a tap and now they go in. From the article above, this seems to be a recurring theme.