I loosely installed the #4 exhaust pipe. Take note: However, while I did expect there would be a little oil behind the temporary fitting, I did not expect the ensuing gusher after the second nut was released. I'll be better prepared for the other 3. After cleaning the mess, I proceeded to fabricate the heat muffs for the two of the other pipes. It appeared easy enough, but the clamping force required for the installation was quite high. The -43B muff was finally completed and I started the -43A but had to stop for the day. Clamp adjustment will wait until the parts are installed.