Thanks for the help on this. Until now, I never knew there’s a decoder ring for belts.
At first I purchased three 3550’s – two to install and one as a spare to keep in the trunk. Then I found the number in the resource directory and on Gates’ website they listed a superseded number, TR22534, so I ordered those Green Stripe belts, instead, which are too short.
I installed the two 3550’s and with the fan eccentric adjustment at the minimum distance, these belts were a mutha to skootch onto the fan pulley. I did it by hand rotating the fan and sliding the belts on. They’re on, but tighter than I’d like them to be; not in love with it. Dayco makes a belt 13A1420, 56″ long x .53″ wide. Or, a 13A1410 that is 55.5″ long.