# Heater housing bolt size?
**URL:** https://59plymouth.net/t/heater-housing-bolt-size/3935
**Category:** Tech Support
**Created:** [May 5, 2025, 5:35pm UTC](https://59plymouth.net/t/heater-housing-bolt-size/3935 "2025-05-05T17:35:42Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@V8PunkRocket](https://59plymouth.net/u/V8PunkRocket)
#### Post date: [May 5, 2025, 5:35pm UTC](https://59plymouth.net/t/heater-housing-bolt-size/3935/1 "2025-05-05T17:35:42Z")
I apologize for what is likely a ridiculous question, but what size bolts are used to bolt the heater housing to the firewall? (707 heater).
I didn’t take my car apart, so its sort of like putting together a puzzle with no good picture of what its supposed to look like. None of the bolts I got with the car seem to want to thread into the firewall. Any info would be greatly appreciated, as Google doesn’t seem to be of much help with this issue.
Thanks!
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### Author:  [@Faulkner](https://59plymouth.net/u/Faulkner)
#### Post date: [May 5, 2025, 9:45pm UTC](https://59plymouth.net/t/heater-housing-bolt-size/3935/2 "2025-05-05T21:45:41Z")
> [@](#):
>
> I apologize for what is likely a ridiculous question…
There are no ridiculous questions, just ridiculous people! 😃 But, here’s a ridiculous answer, from the [Parts Manual](https://www.59plymouth.net/59gallery/thumbnails.php?album=77):
So, we have a MoPar P/N - 1838 158. What does that tell us? Nuthin’! I’m Googling and checking some NOS sites, will let you know if I turn up anything…
Dan
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### Author:  [@V8PunkRocket](https://59plymouth.net/u/V8PunkRocket)
#### Post date: [May 5, 2025, 10:11pm UTC](https://59plymouth.net/t/heater-housing-bolt-size/3935/3 "2025-05-05T22:11:01Z")
Hi Dan,
Thanks for the reply! I have that manual too, and you’re right - that number is basically meaningless! Let me know if you find anything - I couldn’t!
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### Author:  [@Faulkner](https://59plymouth.net/u/Faulkner)
#### Post date: [May 5, 2025, 10:27pm UTC](https://59plymouth.net/t/heater-housing-bolt-size/3935/4 "2025-05-05T22:27:40Z")
> [@](#):
>
> Let me know if you find anything - I couldn’t!
I’ve put the question to Dick Koch, Patron Saint of the '59 Plymouth and Ace Hardware Guru! Please stand by 😃
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### Author:  [@Faulkner](https://59plymouth.net/u/Faulkner)
#### Post date: [May 6, 2025, 5:55pm UTC](https://59plymouth.net/t/heater-housing-bolt-size/3935/5 "2025-05-06T17:55:10Z")
Because I’m such a mensch, I took one of the screws (not bolts) out of my housing for measurement:
The screw is 1" long, the shank is 3/16", overall width is 1/4", the TPI is 10. The head takes a 3/8" socket. Howzat?!
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### Author:  [@V8PunkRocket](https://59plymouth.net/u/V8PunkRocket)
#### Post date: [May 6, 2025, 7:19pm UTC](https://59plymouth.net/t/heater-housing-bolt-size/3935/6 "2025-05-06T19:19:07Z")
Fantastic! I do thank you for your time and effort! Definitely a big help!
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### Author:  [@Dick\_Koch](https://59plymouth.net/u/Dick_Koch)
#### Post date: [May 6, 2025, 9:35pm UTC](https://59plymouth.net/t/heater-housing-bolt-size/3935/7 "2025-05-06T21:35:31Z")
Dan - You the man.
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### Author:  [@Faulkner](https://59plymouth.net/u/Faulkner)
#### Post date: [May 6, 2025, 9:38pm UTC](https://59plymouth.net/t/heater-housing-bolt-size/3935/8 "2025-05-06T21:38:45Z")
> [@](#):
>
> Dan - You the man.
That would be you, Dick! As Ace’s Ace Hardware Guy, would that be a #10 screw?