Hello forum members, I have a problem with a TAV30 CVT/jackshaft plate that will only fit my Lifan engine mounted longitudinally-inline with the cylinder block(not the most ideal position for a rear engined- powered bicycle!!!);I would really like to mount this CVT so the jackshaft end is facing the rear of the engine,but without going to a custom head pipe/two bolt exhaust flange,I would have to mount the TAV30 vertically (which may or may not work on my project motorized bicycle since the TAV30 mounting plate will extend below the eng- ines mounting boss approximately 5 inches(135+mm??)!! There are a few good reasons for mounting the TAV30 vertically;the drive chain to the rear wheel sprocket would be shorter,possibly the center of gravity would be slightly better than the normal position,but most importantly the stock-read inefficient- sardine can shaped muffler can be retained!! I,however,have seen some good deals on a Tecumseh engine specific exhaust header tubing kit that I would not mind buying except for the headtube flange;the head tube flange on my Lifan has 6mm bolts(2) spaced approximately 37 mm apart and I was wondering if anyone at motorbicycling.com know if Tecumseh (mainly3-8 HP L-heads)exhaust headtube flange/gaskets have similar exhaust bolt spacing as my Lifan engine???