SAE flywheel housing

Has anyone heard of an SAE No.7 flywheel housing? I can only find reference to sizes SAE 00 thru 6. It's for a small automotive engine (800cc). Thanks.

I've heard of it but it doesn't show up in most references for autos because it was probably never used as an automotive application.

Try looking in the genset crowd. I think they use the smaller sizes. I remember reading once about a small 2-cylinder engine using a #10 housing. Didn't even know one existed