I am rebuilding the drivetrain in my truck and wanted some input. Building a 400,C-6 and swapping the 203 for a 205. I wil be going to a 33 inch tire and was thinking of running the wide ratio gear set to help compensate for the tires. My thinking is this should restore the lost power from the taller tire while maintaining a nice gear for the highway (rear is 3.50) This should help with performance and mpg in theory.
Has anyone here done this? how do you like the w.r.g. kit? Would you do it again in the future? Any thing I should know/watch out for? Sorry for the long post and TIA for the info.

 

I don't know how much lower first gear would be on a wide ratio kit for a C6 since I have never seen one and never tried one. I can say though that 3.55 is too high a gear for 33" tires. I have that combination now and it is much too high (that situation is being fixed come next week when I have 4.56's put in).

4.10's will restore the low end torque you will be looking for with the taller tires and still allow you to cruise on the highway at a reasonable, though not really fast, speed. I had a truck with 4.10's and 33's without overdrive and it was a good compromise between power and speed. I'm going with 4.56's on this truck because the engine is so small and the truck is so heavy and I don't care about high speed for towing.

You could get away with 3.73's with 33's if the high speed cruising is very important to you. 3.73 would probably be about what you need to make up the difference between the stock tires with 3.55's and the 33's, so your rpm's, power and mileage would stay about the same as they are now.

An axle gear change, even on a 4x4, is probably still cheaper than a gear swap/rebuild on an auto tranny. One other option to consider is leaving your gear ratio the same and swapping the C6 for a granny gear 4speed. Those definitely have a LOW first gear. I think NP435 and T18/T19 were the truck 4speeds Fords used. I think some big Broncos had them from the factory so it would be a do-able swap without custom adaptors if you found the right 4speed.

 

With a wide ratio or not your final drive will still be 1 to 1.While it will help for starting out it won't help once your cruising.Your best bet will be switch the gear's in your axle's.The low gear set for a C6 is 2.72 1st, 1.54 2nd, 1.00 3rd.As opposed to 2.46 1st,1.46 2nd.1.00 3rd.

 

Thanks for the replys. Maybe I was not clear on what I was tryin to do. 3rd gear will be fine on the highway with the 33 inch tire and stock gearing. what I was looking to do was compensate for the extra tire in 1st and 2nd gear with the wide ratio kit which only affects 1st and 2 gears. It should in theory help around town while still giving me a decent rpm at 65 mph on the hwy. Sound logical? Has anyone used this kit and what are your thoughts about it.
Thanks again

 

btt

 

The WR gearset for the C6 is the same as the first 3 gears of an E4OD so anyone who has run an E4OD with 3.50 or 3.55s and 33" tires could give you some input. Basically it's about like running 3.08s with stock tires. The 400 should have enough low RPM torque to make it work pretty well.