Like Roy said run a 3/8-16 bottoming tap in the threads and it'll be fine. I've seen many that were filled with crud or buggered up from someone trying to force in a metric bolt or a bolt with damaged threads. That's a part of every rebuild I do
Problem solved. I guess it was never used, never had snubber bolted on it before. Just re tapped it 3/8. The threads were quite rusty so that was probably the main problem
