Steve,
I've done one with metal bedplate (so as to leave the hull untouched and convert it back to a stock 701)...
But If I had to do it again, will use a GP small shaft to move the engine further back, and do 2 metal beplate as to center the 1100 engine in the middle of the 2 stock motor mounts (instead of moving it forward). Found that moving it forward, the b1 is really nose heavy and not cornering as well as a normal b1, so it's much faster in the straight, but much slower in the corners. It all depends on the size of your track.
Since, I transplant the engine into a blaster 2... and it fits quite nicely too. Same concept, metal plate... so that you can reuse the hull later on with a stock engine.
Have fun...