My oldest grandson (31 years) had a new chevy 1500 5.3 3.73 gears with the 20" P tires. He added a programmer for more performance. Yeah it made the 5.3 run better at higher rpms however having towed his 24' blue water boat before the programmer he found the made the engine struggle more when taking off from a stop sign/etc. Not all programmer work best for towing duties.
The LT275/65-20 E tires are very heavy at around 60 lbs apiece plus the wheel at say 30 lbs makes a lot of wheel/tire load for a small block gas engine to get rolling. Now add more parasitic drag from a 8"-9" wide tire tread has the little small block struggling even more. And it isn't over yet.
The LT275/65-20 show to have a 34" tire diameter which is a lot of diameter for a small block to over come when accelerating.
A OEM LT265/70-17 E would be a better choice for the small block gasser ...... for towing duties.
