Hi Guys,
Just a quick update. Thank you all for your suggestions and comments, this forum has turned out to be a great resource.
So the results of my issue were as follows:
I spoke to a gentlman i used to work with who is a refrigertation technician but is quite handy with metal work. He took a small piece of right angle steel and put some holes in it and then bolted the right angle into 3 of the head bolt threads. This allowed him to hold the cylinder in his vice straight.
He then used a milling maching to put a small hole exactly where the middle of the old bolt was a few mm deep. once this was done, that hole was used as a pilot hole to drill by hand out the remainder of the hole he then used a 1/4 unc tap to retap my hole to the exact size it was.
He has done a fantastic job and you cant even tell anymore my mistake even happend and even better it cost me nothing.
Over all very happy i am able to retain my original muffler. I am thankful for all youre suggestions.
I have attached a photo of the reuslt with my nice new bolt in the hole that was ruined.
![[Linked Image]](https://www.outdoorking-forum.com.au/forum/uploads/usergals/2015/09/full-9525-23809-img_5993.jpg)