Hey I Also Have A Similar Setup,
high torque head
stock header, with biturbo exp.
i hit 40 on flats, have goo torque from and idle, but if im slowing to a stop then start to go it bogs down. i have a main jet at 94 though with alot of plug chops. ut i dont know whrere to get the other jets to tune it out better. but also after running at WOT, after a while it falls flat on its face, i think my float isnt adjusted properly, but i dont know how to set it, because when i do change it either i suffer more bottom end bogging, or less time of WOT, before it falls down again. all i do is shut if off, let the fuel on for a few seconds, then start it again, if i ride with 60-90% throttle, it doesnt hit the bog, or drop off when going down the road, but it does, bog down, if i stop or slow down and re-throttle heavily.
my front sprocket is a 10T, i want to get i think 11 or 24, but counter with a bit on the rear, but i dont know where or what to get for either, and suggestions would be good. i am also planning on CDI, from what i gather the bosch mineralli should work since both garelli and minerall use the same cev and such italian parts.
also my spark plug is an ngk b8hs
and what are you talking about porting what out? the intake port is just about 20 mm, and i know the exhaust port on the "block" is larger than the stock header pipe is. it would almost be point less, now a good polish job for smoothing could make a differance.
oh yes just as an fyi i have a 78 SSXL