I have 2 engines,1 is a -12 motor by measuring the port,D shaped,looks like the fel-pro 1406 gasket would work,the other is a gb2000 more oval shaped so looks like the fel-pro 1409 would be used,can the 1409 be used on both? I used to just use High temp.silicone,but know with changing back and forth from header's with muffler's and with out wanna switch to gaskets for quicker change over.

Thanks,Gary

As long as your bolt holes match up, you can cut the openings in the ports to match your head. I use a die grinder to cut out the material that is blocking the ports so the exhaust leaves without obstruction.