OK, they come as std in 28 and you can get 30s and 32s,can you go bigger from machining to 34 that is the question,Mick.

Definitely

Richard at V Force has put 34's in IDF 36's
I have stock 32's in my 36's at the moment
I am sure you can buy standard 34's for 40's and you could make some 36's that would work

Thanks Barry blue74l or is it now red74l,yeah i just found some at CB perf.34 vents and you say 36 can be made to fit mmmm interesting,thanks,Mick.:thumb

If you need 36mm venturis in your IDFs you probably need bigger carbs. Remember that such a venturi/throttle ratio will be utterly unstreetable, and you don't need part-throttle response on the track.