[mreid]

I agree with the above. Use the Ford lifters and get the whole set. Sometimes they fail and it is really not the engine builder's fault. Now if the valve train geometry is incorrect, that would be their fault, but I don't think that is the case here. Please inspect and verify before you buy! Nothing worse than spending your hard earned money, wiating for parts, only to find they are not the problem. Checking the lifters is easy and only takes a few minutes. Just pop the valve covers and wiggle the rockers. A few should feel slightly loose on the cylinders where the valves are closed. If you truly have a damaged lifter, it will be very obvious!