Jetting a gt750 with pods and pipes

Does anyone have any ideas on jets to use on a 86 GT750 or gpz 750 (same engine) with bs34 mikunis and running 4 pods and a 4-2 aftermarket exhaust?
As far as I can find on the web a 40/140 with middle needle should do the trick, but since they are a bit expensive in England I want to make sure before spending £20 and then having to get more for more £20 and so on.
Any ideas?
bike right now is runing a bit lean with stock jets, has a bit of drop on middle, it just won't rev, unless I cut gas and crank it back up again quickly, plus it has some air backfiring from the pods. Mikuni website points to a lean mixture, so I guess it must be. Carbs are cleaned.

If the header has a reasonable street baffle (not straight pipe) my GUESS would be to go up about one or two sizes on the pilot and two sizes on the main for a starter point. That's just a guess based on what I have read.

Actually they are straight pipes. so I guess 125, or 127.5?

Have no idea. I think with straight pipes, you can pretty well forget about them ever running right again. The engine needs some backpressure to work right and the carb needles are not designed for straight pipes. I recommend putting mufflers on it.

Just sent it to a dyno. Actually it is possible to make it work. iddle screw 2 1/2 out, pilots 32.5 mains 140 K&N oval pods. 64hp to the wheel (1,5 less then 26 years ago) and 41,5 torque (again 1,5 less then 26 years ago) cam timing had to be changed. But runs great.