View Full Version : snapped rocker stud on rebuilt gt40 351

08-11-2013, 09:20 AM
After chasing down and checking everything with the drivetrain I realized the vibration in my boat was due to a skipping cylinder. A compression test showed only 15lbs or so on cylinder 1 so I pulled the valve cover and found a snapped rocker stud.. I assumed it possibly wasnt torqued and came loose maybe so simply replaced the stud, retorqued and put it back together. At first it seemed fine as I idled away from the dock but as soon as I gave it the slightest throttle tue vibration came right back again.. I havent taken it apart yet to confirm but im assuming it snapped the stud again.
My rebuilt shortblock and rebuilt gt40 heads only have about 20hrs on them now, and it was running perfectly up to this point.. I reused the stock 351 rockers, pushrods (all seemed straight upon assembly), and rocker studs.. I got the heads freshly rebuilt from someone on CL so cant speak to the quality but all appeared perfect visually..
Any ideas on this one???