Jean & Leroy:
West of Alamosa and between South Fork and Pagosa Springs you'll be crossing over the 10,850 ft. Wolf Creek Pass. With your 340 Cummins and towing your CRV you'll do o.k. BUT it'll be a slow pull to the top AND...coming down the steeper West side of the pass down into Pagosa Springs DEFINITELY use your engine/jake brakes. If ya don't have em.....be very very careful and DO NOT overheat your brakes!!!
After Pagosa Springs, you've got no problems.
Just for your info, we hauled Wolf Creek Pass with our 45 ft, 500 Cummins, towing our Honda Element, and though we were pulling pretty hard near the top, we had no problem. If your worried, just unhook your CRV and follow your Allegro over the pass. Oh, also, there's no worry about twists and turns and, DO plan to stop at the turn our rest area atop the pass.
Steve & Lynette
2014 Newmar 3103 BAYSTAR/Triton V10 w. Banks/05 Honda Element toad