New ARP Head bolts

[pheyden]

In recent times I have noticed that many of the old head bolts, that I have salvaged from motors over the years, have actually stretched beyond acceptable limits. The reasons for this as not entirely known and it could be from over stressing, or inferior material. It is quite easy to check them with a "thread pitch gauge". If the gauge does not ACCURATELY follow the threads, the bolt has stretched.

I have made arrangement with ARP, the specialty automotive fastener company, to make a special 9 x 1.25 replacement bolt for the Fiat/Autobianchi engines. These are 180000 KSI steel bolts with undercut shanks.

We will be running a special on these bolts in May.