The technical edge:

My personal favorite is to smear some clean grease to burnish each side of the gasket and fit it without using gasket cement

The main body is 9-1/2" long and 5" diameter and they hold 3-1/2 quarts of oil

and bolt to the front crankcase bolt and then to your exhaust pipes that have tabs or threaded bungs for a nice sturdy pipe mounting

and sometimes in zinc plating

Solo Seat Weld-On Threaded Spring Mounts Finish_Raw The technical edge:From Lowbrow Customs: Mount your solo seat easily with these weld on solo seat spring mounts. Made of 1018 cold rolled steel for easy welding, they are 1" diameter with a threaded 3 8" 16 shaft for the spring to sit over. They are coped at 1" to fit standard size frame tubing, but can easily be enlarged to fit larger 1 1 4" tube if necessary. Included are a heavy duty chrome steel washer and a chrome nylock nut for each mount to secure your seat