That would be a possible best solution but require lots of changes. Given the age of those engines and the numerous configurations they had, it is likely not available.

I have a bit of experience with the 3208. Belt failures are common because the design requires two matched belts, any slight differences in length or "V" angle will result in one belt taking most of the load until failure.

Further if one of the belts is shorter even very slightly,bring the belts up to tension, the shorter belt will be forced deeper in to the pulley's "v" groove so the effective driving/driven diameter of the pulleys will be different between the belts causing a fight between the belts and very early failure.

This is also quite common on other engines or applications where multiple "V" belts are used.

Gillig supplies these belts, or used to, in matched sets.

Second Ed’s suggestion (see above)! Most 3208 engines come in Gillig chassis and they were the backbone of their transit fleet. We are a very small number compared to that and they used Gillig belts and did not have any reported issues. It’s not hard - call Gillig!

When I worked for Dometic they had a Monaco RV from California with a Cat engine that I used on occasion, every time I drove the damn thing it blew the belts. I guess Dometic should have Called Gillig!!!!

On the 3208T in our Beaver we used belts directly ordered from Gillig. Never had a problem. PO told us about his search for the right belt and seriously: order directly from Gillig. Yes they will laugh when you mention a 1984 MH but they send it in a box to your door step.