Hello All first time poster and tried to search for this as I am sure I am not the first to ask. I got a new used boat with a mercruiser 1996 454 mpi. I had it winterize professionally which I use that term loosely as they didn’t put all the plugs in. Got in the back country and she was leaking like a sieve on startup. Looked on the starboard engine block and it’s missing a drain plug. It looked to be 3/8” and I had a steel 1/2” that did not fit. My neighbor had a 3/8” blue plastic drain plug and that fit in. I looked online at the parts break down for my motor and it shows first using a bushing that I could not see any dimension information online but looks like it goes 3/8” into block to 1/2” then using a 1/2” plastic drain plug. Is there any issue with just using the 3/8” right into the block?