Towing w/ 72 3/4 ton

[Mertz]

I have the 350 running as well as possible. I have a Cliff Performance Qjet on an Edelbrock intake with MSD ready to run ignition, 1.5 roller tip rockers with correct geometry on the push rods, ceramic headers with proflow dual exhaust with cross over pipe. Timing is at 36 initial plus mechanical all in at 2500. The 350 trans has a shift kit and was recently rebuilt. Tires are LT24575R16. I am pulling a 5000lb trailer and it pulls ok on the flat but has to really work hard to get it up a long 7% grade. I believe my rearend has 3:08 gears. Would going to 3:55 or 3:73 help without loosing too much gas mileage when not pulling. I am getting 15mpg now. I only pull the trailer twice a year.