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I had to change my thermostat housing as it was pitted and leaking. One bolt was I think the original 3/8"-14 x 7/8 so says my bolt gauge. Which is a hard to find size. The other had a metric bolt stuck in that happened to fit.
I checked Kanter and Mxz Merrit. Where do you get these bolts?
Thanks
John

Are you sure about 3/8-14? Packard parts list says they are 3/8-16 and that's a very common bolt, available at my local hardware store in 1" length for about 75?. If that's too long for you, add another washer or grind a tad from the length.

To the best of my knowledge there were no metric screws used as ordinary fasteners in a Packard. Parts manual says for the thermostat flange (except for the 22-23rd 356 engine) all engines from 48-54 used a 3/8-16 x 7/8 hex head bolt and a 3/8 lockwasher. That size should be easily found although the length may be a tad longer. If it absolutely needs 7/8 and you cannot shorten then McMaster-Carr carries 7/8 in various grades and metals but you will need to buy a box of them to get the 2 needed..

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Thanks. I looked again. I miss read the bolt gauge.
John

If someone did a dirty trick and rethreaded a possibly damaged hole to metric then several hardware stores carry a small selection. I believe Lowe's and possibly Home Depot might also have a few. If no luck buying them locally then McMaster also carries metric sizes in various grades and materials but you would need to determine the size needed.

John if you want to play it safe, go to the local hardware store and buy a few 3/8 - 16 one inch long bolts. Before you install the T-Stat goose neck, thread the two bolts into the head and run them down until you encounter significant resistance . . . but take it easy. Then try to slide the 'ears' of the housing under the hex heads. If you can't slide the housing under the heads that's good . . . you will have at least both the gasket and lock washer's thickness as margin. The plot thickens a bit if you can slide the housing ears under the hex heads . . . That's the minimum amount of material that must be removed either from the length of the bolt, or the thickness of 'extra' washers that must be added.

I suspect a lot of tolerance 'stack-up' went into the determination of the 7/8 inch both length. That is every head/housing combination would be leak free, and not jam the bolt into the bottom of the threaded hole. Your head/housing may easily accept bolts that are one inch long.

dp

Thanks everyone. It doesn't seem like it was rethreaded. The old bolt wasn't super tight.
John

You should chase those threads before putting new bolts in.

Will do. Thanks
John