I guess it doesn't matter now, but for anyone else who wants the info....
The SD-1 will not fit without cutting it down. The CAR-1 fits just by removing the end cap. You can leave the end cap on if you use the crush washer.
The Car-1 is available with or without the white writing on the side if you prefer the all black look.
I remember a thread awhile back that had a custom made fake can that was bigger like the SD-1, but didn't require any permanent modification to either the rifle or the can itself. I would have gone that route if I had read it on time. Oh well, I'm happy with my Car-1.
Mine and a friend's. He had to get a 15-22 after shooting mine. Both have Spikes CAR-1's.