I just bought a Trail Lite B+ 211s with 8.1 Chevy engine. This is my fifth motorhome (others range from an old 20' Vagabond, and three Winnegagos, from 19 to 32'. This vehicle is fantastic. I am...
Sorry folks I just couldn't resist. At 62 years of age, i have had quite a enough "rear-end rations" thank you very much.
To answer the question, yes you would probably get some improvement MPG with a 3.73 "rear axle ratio" swap, but your towing ability would be compromised. And acceleration would probably be reduced somewhat. Probably money better spent to go with an under/overdrive unit in the driveline.