Is that a vertical shaft Briggs?
Reason I ask is keep a heads up about the governor stuff when you lift the bottom sump off, sometimes the governor shaft comes with the sump and small pieces may fall into the block and not be readily apparent until you start up the repaired engine and no governor control and or gear teeth get sheared from small metal pieces inside, make sure all governor stuff is ok before re-installing the sump. If you mess up you will have to buy new gaskets again. If you are not real familiar with what to expect make a trial practice go stabbing the sump without using a gasket the first time.
Also I like to take all the crank end play to minimum specs so as to keep the crank from pecking on the sump.
I sometimes have to make shim washers for the end of the crankshaft to get the end play to minimum specs.
It's quite common for a new gasket to start leaking if all is not cleaned good and care taken and I try to keep the gasket as thin as possible. (some briggs have different thickness gaskets or stack paper gaskets so as to get some crank end play if too tight) specs and the more stacked gaskets the more likely of future failures IMHO)
Check the end play of the crank before you take the sump off. Then mic a piece of the old gasket after you get the sump off. I made a steel plate that I can bolt to the side of the engine for the magnetic mic holder so as to get a real precise end play reading. I have also found that getting the crankshaft end play to minimum specs reduces or completely removes the harmonic engine knock that some Briggs engines have a certain engines speeds.
Someone posted a question thread on here awhile back, several months ago about sump gaskets leaking on Briggs engines and several good tips about how easy it is to have a new gasket failure. Keep in mind the aluminum sump and block is expanding and contracting as the engine heats and cools. I've seen them sump gaskets seal ok when cool but leak hot oil real fast when the block gets warm.