B-body K-member attach bolt threads

Hey Gang...

I'm in the process of starting to restore 69 Charger 500.... Question; are the threads in the front framerails for the k-member attach bolts tampered or standard threading. I'm looking to clean them up since there is some corrosion in there... But, don't want to ruin the threads of a run a tab in them...

Thanks..
T

If you look at one of the bolts it will answer your question.

I have, not green around the ears, but also wanna be better safe than sorry... My gut says they aren't tampered, but I'd rather get a second opinion...

Thanks..

The threads are not tapered, but the bolts have a bit of a tapered shank to help center the frames on installation, I believe.

Threads are a straight thread tap. 5/8" coarse thread going off memory

Bolts are as well...but have a shoulder on them to position the K frame

Are you sure about that? Everyone I have has a taper at the start of threads. I probably have about 100

Bolts have a pilot point to aid starting them but has nothing to do with thread pitch .

Thanks guys... Wanted to make sure....

I've taken a bunch of Mopar K members out of A,B,E and even a few C body cars, all of them use the same type bolts with the tapered ends with the cleaning slots in the bottom starter threads

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5/8? I figured they were larger. Been awhile since I changed a K-member.