Hi Ralph,

Thank you for the reply.

The regular straight plug version 70 twin uses CM6 plugs. To narrow the engine they angled the plugs down and use the smaller plugs. I'm hopeful it will fit in my 50cc Aeroworks Extra 300.

I guess if the 1/4-32 plugs don't work out the cylinders could be drilled and tapped for the cm6.

After searching I found NGK ME8 plugs. Why are the rimfires better?