What bit to use to enlarge this....
 

I got a bigger throttle body (98 GSR throttle body to be exact) for my D-series sohc vtec motor,

and obviously since this throttle body is much bigger than the one I currently have...

I need to match the size of the new larger throttle body too my intake manifold.

so I got a dremal tool here, and all I need is a bit too use, is there any particular bit that I should use so I can match the bigger size of the new throttle body too my intake manifold?

before you do anything...please ensure that u have the intake manifold off the car so u dont get metal shavings into the engine...or I suppose u could stuff a rag down the intake manifold and hope that when u pull it out no filings come lose and end up in the engine

a die grinding bit will work for you

uh..thats going from 54mm to like 62mm. have fun with you bad idle and absolutly no bottom end. you should sell the GSR tbody and bore your existing tbody to 58mm, that way you have no problems.