I see you already got the job done but another product that I used for about $20.00
Loctite ® 518™ Gasket Eliminator ® Flange Sealant
Recommended for use on rigid iron, steel and aluminum flanges e.g. aluminum gearbox and engine castings, etc. Easy disassembly and cleaning.
Loctite® 518™ Gasket Eliminator® Flange Sealant forms a flexible, solvent-resistant seal that will not tear or decay. Seals to 300 °F and fills gaps to 0.50". It can be used on flexible metal assemblies, including aluminum surfaces.