When I purchased my first Amazon a few years back, the seller told me the B18 engine block had been bored out to accept B20 size pistons. I ended up putting a B20 F head on it, along with a 2.25" exhaust. Well, during the engine rebuild, we discovered that the engine was not bored out as advertised (people really disgust me sometimes), and actually was just a plain old B18.

I am wondering if the 2.25" exhaust is too large for the engine, and curious if I should go to a 2" or even 1 3/4" system. The exhaust system on the car is pretty new, and I'd hate to replace the whole thing. Short of buying a new exhaust, is there an easy way to decrease the diameter of the exhaust (maybe by welding on a smaller tail pipe or sticking a banana in there or something- maybe not a good idea)