I am replacing my oil pan on a 485 merc and some of the bolts are rounded and also mix matched and want to replace them all with new, so should i just match them up at the hardware store or should i be getting actual oil pan bolts
Personally I've always tried to keep the hardware OEM if possible just for the less hassles of "wondering" what material was used where as they tend to differ in certain areas vs others to help lower corrosion type issues.
Either way it looks like you'd need 29 of both screws and lock washers if desired and I found some bolt sizes for your engine model to help compare against should you go out shopping, https://www.crowleymarine.com/mercury-outboard/parts/1064_13.cfm?mdl=YPNNAB
well thats seems pricey think i will see how much they are going to cost at hardwware store, considering that some of these bolts were 38 years old, and i will be watching them for corrosion and pulling motor more frequently now that i am set up to do so. As much as i would love to keep them OEM my list of stuff to do this winter is huge and costly, the big one is a new boat deck. Already have the oil pan and gasket and a awesome used flywheel which were both compromised by rust so badly from sitting for 15 years. I should of bought a new boat, but the learning and repair process has been great and i know so much now i hate to start over with something else LOL
When we repowered our small cruiser's V8, pulling it a couple times to fix oil leaks (long story) was not that fun, and always at an unfortunate time. I'd go with OEM pan bolts, but hey, that's my .02 - but you may want to think of stuff like this when comparing cost of engine components, and deciding which ones to get
MC v8 350 use 1/4" and 5/15' common thread on pan. I am not familiar with your motor. Mine were rusty but not unsalvageable. Nonetheless, I went back with 1/2" and 3/4" long ss bolts with ss star washers.