I find this very interesting I have my 66 c30 292 sm420 all stock towed my trailer 31 foot two times this summer on the highway not to bad as long as I kept the speed up but on country roads where I could not get the runny might go up a hill at 20 to 25 mph couldn't even imagine doing this with a three speed trailer does weigh 6000lbs empty I am thinking of headers manifold and cam maybe even roller rockers sounds like it might help overall though it is fun to tow after i got the hang of it.
Anyway good luck
Dave
