Getting ready to purchase a 350 ccsb in the next few days and can't decide on 3.73 vs 4.3. The truck will be used to tow a12000# conventional trailer hauling skid steer and excavators over short distances with no hills or highway. Truck will also be used as a daily driver and on the beach in soft sand and plowing. Probably less than 2000 miles a year on the highway but when on the highway it will be driven around 80mph. I have an 08 5.4 with the 3.73 now which does not love towing even on local roads but it also struggles driving 80 on the highway. I have never driven the 6.2. I have found available trucks set up they way I want with both rear ends. Thanks in advance for any advise

 

I would go the 4.30 gears if I were you. Better towing capability and you won't notice the small decrease in gas mileage. You get a max of 12,300 lbs towing with the 3.73 compared to 15,000 with the 4.30. Also GCWR goes from 19,500 to 28,700.

 

is all in the gearing , esier on everything .. less lugging the better

 

Thanks for the quick response. Do you feel driving on the highway unloaded at 80mph will be annoying or have a dramatic effect on mpg?

 

I have 3.55 in my 13 f250. Tow 20k regularly. Never wished I had more power or lower gears. Enjoy the lower rpm on the highway. New 17 I ordered Monday is a 450 with 4.30s though. Reason being I ordered a much larger tractor and heavy batwing. Will be closer to 30k trailer weight.

For reference, my empty GN is 7700 and you hardly know it's behind you. I drive like a grandpa but it's a minor affect on performance

Brett

 

Get the 4.30s I have them and love them. Some have said you can get better mpgs around town if you live in a hilly area(which is my driving conditions). I've never calculated my mpgs, I barely pay attention to what the dash tells me. Have zero complaints

 

I have the 4.3s and the truck will cruise to the speed limiter like it's nothing. You can cruise comfortable at 85 and still don't hear the engine. But don't be fooled, 75mph cruising =13mpg and 85 was even lower.

 

I have the 3.73 gears (wish I could have waited for 4.30) and get 13mpg with a mix of driving. So apparently not much difference at all

 

I have never been one to follow MPH, I live by the Tach. the 6.7 can run near forever at about 2000 rpm as you go past that mpg drops like a rock, DEF consumption skyrockets and oil life decreases....

 

You will certainly have a dramatic effect on MPG's driving 80 mph with either 3.73 or 4.30 gears. The limiting factor is not the gearing, but the aerodynamics of the truck.

The 4.30's will get you slightly better mpg's in the city. (stop and go) While the 3.73's will get you slightly better mpg's on the highway. Both assuming you are running empty/unloaded.

If you tow, then the 4.30's win in both categories.

IMHO...go with the 4.30's. I know I am super glad I did!!


biz