Head Bolt Wrench

If the car is a 700 then they are six-spline bolts but if a 900 they are twelve spline bolts IIRC. Most accessory stores should stock them (like Halfords in UK), possibly IPD (Portland, Oregon).

Cheers, Peter.

I've worked on all my cars and others for 40 years, but never run across this problem. We have found that they are "triple square", 12 tooth splines, 12 mm. S-K makes them for $12 and Hazet makes them for $25, from Germany.