Helicoil for rocker shaft on a 455

So I’m building a street motor, 462ci... While assembling the motor, I put the heads on and when tightening down the shaft one of the mount bolts pulled out... I chased the threads on both the bolt and the head prior to assembly .. Wondering if anyone had put a helicoil on a head? I see that there’s a small hole off to the side of the pedestal mount bolt hole, oil hole? It’s close, concerned that it’ll have too thin of wall thickness if I do it......
Anyone done this????
Thanks,
Gary G

 

I was thinking maybe if I went metric it could work out.. I’ve never messed with those, even thought it’d be a “bastard “ hole, I might just be able to remove minimal material by cutting new threads...

 

However you resolve the issue, ... I believe using a stud is easier on the threads in the head as there is no friction during the torquing process.

Larry

 

I talked to my “engine guy”, he says a helicoil’s the way to go...

 

Done helicoiling, almost done with assembly...
Just a little street 462.....

 

Who's rockers are those?

 

Mine...... Proform 1.65 roller rockers.

 

I got a deal on them....

 

nice!

 

Thanks.....

 

Not to hijack the thread, but have you used those rockers before? Just found out proform made those...

 

No,first time with them.........

 

Helicoil is the right solution, my TA SE heads have helicoil from factory.