To Heli Coil or not- that is the question

[CUDA JAS]

I have a striped header bolt in on my 360 (the wet one of course).

I know I can heli coil it, but if I am going to drill it out anyway, can I not drill it and tap it for a larger bolt/stud or am I missing something).

I have both the heli coil to bring it back to origional size (5/16 i think), and a larger stud (3/8).  Other than haveing a different size nut on one stud, is there any reason not to do this?

Jason

[hemiken]

The only problem i see is if your  headers are large and you will not be able to get a spanner on the nut if it is too large  because of the pipe size of course.

[Chryco Psycho]

going to 3/8 is ok but not I deal as it will get close to the header but helicoiling it is worse , now you have 2 sets of threads to seal & this rarely works , what you need to use is a timesert , itis a metal sleeve that will not leak once installed , going to 3/8" may still be the best option though

[moper]

 

[Bluemonster71RT]

I had put a heli coil in my 383 and it always leaked both coolant and did not seal the header as good so 

[wagesofsin]

timesert is the way to go. maintains the original thread size , and material integrity.

heli-coils are junk , not saying they wont/dont work.....

this may start a humbug, but i know it to be true.

[heminut]

I've used heli-coils for years in aluminum and they have always worked great. Most of the time it has been in Harleys, which are air cooled so there's never been a coolant leakage problem. I agree with CP that it would be next to impossible to keep a heli-coil from leaking coolant.

[Changin Gears]

I think MR. Gasket sells some header studs that are 3/8" into the block and 5/16" for the nut.

[moper]

I've always just gone to the next size up on those holes. But that only works once per hole...lol.