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Discussion Topic:
1937 Ford firewall hole size
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1937sedandelivery |
12-11-2015 @ 4:00 PM
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Senior
Posts: 501
Joined: Jul 2014
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Hello, There are a number of stock threaded holes in my firewall, in particular, the ones that go along the bottom edge where the top of the floor boards are attached. There are nuts welded in place for these. The thread size appears to be 1/4". I have tried both coarse and fine threaded bolts in these and don't get very far before things bind up. I plan to chase the threads but don't know whether to use a fine or coarse thread tap. I suspect they are fine threads. Any confirmation? Thanks guys, Gregg
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40 Coupe |
12-12-2015 @ 5:27 AM
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Senior
Posts: 1675
Joined: Oct 2009
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The nuts are not welded in place but crimped, peened or swedged D-nuts. I believe they are 1/4-20 thread. Suggest you use some penetrating fluid on each hole and try to find one that will accept the screw without tapping. Once you confirm size then tap. Roy Nacewicz sells replacement D-Nuts of various sizes.
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37 Coupe |
12-12-2015 @ 5:34 AM
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Member
Posts: 362
Joined: Oct 2009
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I believe for some reason these require one of Henry Fords strange pick in a non standard size. As I remember they may be a #12-20 thread which is about .218 instead of .250. Check with Roy Nacewicz and just buy the correct size,he has them or used to.
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1937sedandelivery |
12-12-2015 @ 7:19 AM
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Senior
Posts: 501
Joined: Jul 2014
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Thank you for the quick responses. I have ordered parts from Roy before (good guy). I will hit him up for the correct screws. Gregg
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1937sedandelivery |
12-12-2015 @ 6:47 PM
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Senior
Posts: 501
Joined: Jul 2014
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Hi 40 Coupe, You are correct. The hole threads are 1/4"-20. I chased them with the correct tap, with very little resistance, just a bit in order to clean the rust and some primer out of the threads. Floor boards are going in this weekend! Thanks, Gregg
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