Thread: Cross threading

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I am installing new headers on my 350. While taking off the driver side header I noticed the second header bolt to the front had been force in and cross threaded badly by the previos owner or who ever installed the old headers for him. I got the old bolt out but I can't get a new bolt in there with out forcing it. I realize this is probly a newb question but is there a way to fix this?

it would be easy to tap it

You need to get yourself a thread tapping tool of the correct size,,gring one of the bolts to your local parts store or rental store if you dont know the size and either rent, or buy a suitable thread tap.
once you've got the tap,,start the tap into the thread bore in question and be carefull getting it to start straight,,then take it slow and twist it in and out in 1/4 turns,,increasing at each turn,,until you are all the way in.
Then you should be good to go.

If the hole is boggered up too bad to get it retapped and have good threads, then install a helicoil. The thread size is 3/8-24

"The thread size is 3/8-24"

Is that the Chevy size?

Most header bolts I run into are 3/8-16 (NC)

Originally posted by C9x
"The thread size is 3/8-24"

Is that the Chevy size?

Most header bolts I run into are 3/8-16 (NC)

Or in the odd case, if they were STUDS; they would normally be 3/8-16 (NC) on the block side, and 3/8-24 (NF) on the outside. With a 3/8-24 nut.

Jay, That you? (C9x)

"Jay, That you? (C9x)"

Yep . . . my Nom De Plume....

(They require three letter names on this board.)

Yup, 3/8 16. It was early and I was thinking the nut side of the studs that we use for headers. Sorry for the mis information. The head is tapped 3/8-16