When I did my R77s the first time, the packing kit came with a full batt of insulation and a cut piece of about 1/3 of a batt. I tried to wrap both pieces and had a hell of a time stuffing it into the can. I figured out the best way is to wrap the full batt around the pipe, stuff it in the can and then take the loose pieces from the cut batt and stuff them into the open areas with a long stick. Worked perfectly. Yoshi says to repack at 7500 and 10000 miles in two different places on their site. After doing it twice I think you can go at least 15-20K before repack on carbon cans and probably more on stainless.