MTFCA Forum

Hello, I need to clean up the threads on a 25 exhaust manifold. What is the thread size?

Thanks

1 7/8-16 thread size

Humm, That is the size die I purchased. I would guess it is a 1/4" to small. It is an OUS made thing, I did not measure it to confirm the size, but it is stamped with the correct info.

Edit: I just looked on the website I ordered it from. I ordered a 1-7/16 x16. I guess I need to return it and get the correct one.

Thanks for helping

Where are you ordering the die from? A quick Google search list prices around $100. Is this a rare exhaust manifold you are trying to re-thread?

It's to clean up the threads. I found one on Zoro, for about $80, never hear of them before.

Good to know. This one is nice and flat. Everythng looks good, but the threads look like crap.

"Flat" is a misnomer in T language ! One needs to verify the "droop" in the manifold by holding a straight edge at the BOTTOM of #'s 1 & 4 to see just where #'s 2 & 3 are - most the time the center ports will be way off !

Thanks, the center two on those one has about an 1/8" droop.

Then dont waste your money on a die until you straighten it.
Or put you money into a new one.

jagiven wrote: ↑

Sun Apr 07, 2024 2:14 pm

It's to clean up the threads. I found one on Zoro, for about $80, never hear of them before.

$17.60 - https://www.ebay.com/itm/126307511183?i ... R7rT3ajXYw

Jerry
That is a great eBay price on the 1 7/8 X 16 Die.
But check cost of the Stock before buying.
Ron Patterson

Thanks Steve for the detailed write-up on your page. Also hope your recovering well.