starter support strap bolt
Thread Starter
Le Mans Master
Joined: Nov 2004
Posts: 7,850
Likes: 142
From: Tampa, Fl.
starter support strap bolt
Old C1/C2 guy, here, checking in with all you fine C3 folks with my first post. Just wanted to say howdy and also see if you all might be able to help me out.
Last year, I acquired a 1972 LT1. This year, time was finally right for me to do a few things to the car.
The M20 tranny made lots of noise in the first three gears, so I pulled it out and put new brgs/seals/gskts in it. That fixed the noise.
I would like to reinstall the starter support bracket and shield. Can you tell me what bolts are correct? The block hole looks like a fine thread, yet a 1/4 NF is too small and a 5/16 NF is too large. That only leaves metric. Tell me it ain't so! Anyway, if someone has a pic of the starter area, and some bolt sizes ant types, it would be a big help. I looked in several of the vendors parts books and also the AIM, not much help, there.
I will be parking myself here looking for guidance just like Paul 74 did some time ago.
Regards,
Chuck
Last year, I acquired a 1972 LT1. This year, time was finally right for me to do a few things to the car.
The M20 tranny made lots of noise in the first three gears, so I pulled it out and put new brgs/seals/gskts in it. That fixed the noise.
I would like to reinstall the starter support bracket and shield. Can you tell me what bolts are correct? The block hole looks like a fine thread, yet a 1/4 NF is too small and a 5/16 NF is too large. That only leaves metric. Tell me it ain't so! Anyway, if someone has a pic of the starter area, and some bolt sizes ant types, it would be a big help. I looked in several of the vendors parts books and also the AIM, not much help, there.
I will be parking myself here looking for guidance just like Paul 74 did some time ago.
Regards,
Chuck
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
There are no "fine" pitch threads anywhere in the engine block [to my knowledge]. I'm pretty sure that in '72 they were all American-coarse threads. GM didn't 'force the issue' on metric components until the mid-70's, as I recall. Most of the threads in the block are 3/8"-16NC; but there are some 5/16-18 and just a few 1/4-20 threads.
Thread Starter
Le Mans Master
Joined: Nov 2004
Posts: 7,850
Likes: 142
From: Tampa, Fl.
Well, after three votes for coarse thread, I crawled (moan) under, armed with 1/4 and 5/16 NC bolts. You guys nailed it, 5/16 NC. The coarse thread usage in cast iron is logical, and should have told me something.
I looked into the bolt hole when I was under the car and had the transmission out, and thought it was fine thread, never even considered coarse. That was also good info regarding the metric usage. As I recall, GM limited the use of metric fasteners, at least initially, to body components. I am used to wrenching on the older vettes.
Thanks for the prompt replies.
Chuck
I looked into the bolt hole when I was under the car and had the transmission out, and thought it was fine thread, never even considered coarse. That was also good info regarding the metric usage. As I recall, GM limited the use of metric fasteners, at least initially, to body components. I am used to wrenching on the older vettes.
Thanks for the prompt replies.
Chuck
