Looking for a timing recommendation for towing a vintage camper that weighs about 2000lbs. with my 49 3/4 ton and stock rebuilt 261. Right now the timing is adjusted by the vacuum method (maximum vacuum minus 1" vacuum) while the octane selector is set at 0. Should I leave it alone or retard the timing with the octane selector? The truck does have a T5 transmission and 3.54 rearend. Dave V
