WHEN ACCELERATING ON A FLAT STRAIGHT HIGHWAY FROM 30 MPH, THE TRUCK JERKED TO THE RIGHT WENT INTO THE DITCH AND ROLLED SEVERAL TIMES, TOTALLING THE VEHICLE. INVESTIGATING OFFICER COMMENTED THAT THE BOLTS THAT HOLD THE CAB ONTO THE FRAME ONE WAS MISSING AND ANOTHER WAS SHEARED OFF. TRUCK RECENTLY HAD A REBUILT TRANSMISSION AND ENGINE INSTALLED AND HAD HAD REGULAR "SAFETY CHECKS" AT A LOCAL SHOP. NO NOTICABLE LEANING OR OTHER INDICATORS THAT THE PART WAS ABOUT TO FAIL. THIS KIND OF BOLT SHOULD LAST THE LIFETIME OF THE VEHICLE! NLM