I want to replace the phillips head screws with socket head screws on my OS .40 LA engine. What are the correct sizes for the muffler, backplate, and cylinder head screws? Thanks.

Beau

I am pretty sure that the muffler screws are 3mm and would guess that the rest are too.

Yup, there 3mm, I replace all mine with socket head cap screws from a hardware store, Kept stripping the original ones.

Dauntae