I would say that would work fine.. You could put a steel rule on edge and see just how flat it is..Check a few spots with a feeler gauge underneath, .001 doesn't go in your good...or even get down and see if you can see light underneath the straight edge, shine a flash light behind it... Another thing I use as a sealer that never hardens is Hylomar.. works great. It was developed for Rolls Royce to use on their jet turbines to seal up any oil leaks when they started using synthetic oil.. I used it at Harley... A one shot deal.. They make a spray too.. You can coat stuff and put it together a week later... Some people over apply sealer,, if you do with hylomar, fear not, it will not plug any oil passages inside a motor... We saw a few lower end crank pin oil galleys plug with regular RTV silicone which took the lower ends out from lack of oil.. Someone had applied too much silicone on a cam cover.. Hylomar great stuff, not cheap but easy to take back apart and clean up and no oil leaks... I use to dip 1/4-20 allen screws into the end of the tube and coat the screws that had oil sitting behind them on a primary cover etc... Good stuff.