I have been looking for a freeze plug for the back of the engine behind the flywheel. Its hard to figure the exact size, near as I can tell its approx. 2 5/16 or 58.72 mm. Very odd size but can anyone get the exact size? I have tried rubber expanding ones that don't work very well. I am to the point that I may just weld the cam plug I have that is a fraction too small into it. the engine was rebuilt but this plug was never found. I exact measurement may help of which I am unable to get. any help would be great.