Tools & Fabrication - Cylinder head porting tool?

Where or what can I buy so I get to the inside of the intake port on a 241 casting cylinder head? My dremel shank is only so long and the tool body starts to hit the cumbustion chamber and I need somethign longer what can i use. Dremel.com has nothing longer than the regular size one that I could find. Anyone help me out?

Thanks

I bought long-shank carbide burrs off eBay and used
them in an electric die grinder (ditto). Ball, flame and
a couple of others. I used a dimmer to control the
grinder speed and a welding glove on the burr shaft
to keep it from whipping / skipping.

Thanks! I will keep looking I think Whislter has one that he has that I may barrow