How big can I bore a B18A Throttle Body?

[RFHOMI2U]

My friend is a machinest, and he said he would be able to bore my throttle body off my OBD0 LS motor if I told him how big he can do it. Does anybody know how big I can bore a stock LS throttle body to? And how big is it right now? - Thanks

 

[NoJokE]

You could measure it with a tape measure. I dont know exactly off the top of my head how big it is.l

 

[JDMilan]

if i am not mistaken I believe it's only 4mm over stock, not sure though