Boiler's 3/8" shims or equivalent?

[hannasm]

But they do not always fit and you have to redrill them

I put a pair on last weekend and i had to grind a good chunk from one hole on each plate with a burr grinder to get it on.

 

[tommudd]

I put a pair on last weekend and i had to grind a good chunk from one hole on each plate with a burr grinder to get it on.

reason why I never use them on any of the builds we do here