i think anything in front of em will cause flow issuues, even the stock style filter. if there was ever an argument for an airbox, the TBolt is it.
i dont see an advantage in this machine for a mikuni, since the AMAL
is in good condition and appears to work correctly. ive taken the machine out and have spent time going up and down the throttle pozitionz to check the mixture. works fine on the needle jet, needle, and slide. no sign of leanness on the 220 when rolling the throttle off but if it works just as well with a 230 ill put one in and leave it.