[font size="1" color="#FF0000"]LAST EDITED ON 02-Feb-01 AT 02:06 AM (EST)[/font][p]I've got a question for you tranny gurus out there. I'm looking into swapping in a built 460 into my '88 Bronco and I know I will have to go with a big block C6 4x4 tranny (current AOD won't bolt up). I currently have my axle gearing at 4.56 to work with my 38" tires. What I'm wondering is this- is there a numerically lower 3rd gear swap possible for the C6 trannies? I'm not worried about the 1st gear as the 460 will have more than enough torque to get me moving but I am concerned about the rpms at highway cruising speeds. I am aware of the wide-ratio kits available, I'm wondering if the opposite is too. I also do know about the OD add-on box (Gear Vendors) but that is not an option due to wheelbase length and cost. Any pointers? Also, an E4OD is out of the question as well due to the cost of the tranny and electronics needed to operate it.

Thanks,
Dustin Siebert
mrlaserboy(No Email Addresses In Posts!)
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'88 Bronco XLT 302EFI/AOD/BW1356/44IFS with 8 lugs(open)/10.25 FF(Lockright locker)/4.56/6" Superlift/2" BL/35's-street/38.5's-trails
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3rd gear on a C-6 is 1:1 and cannot be changed.

The tach will be a few % higher than the output shaft speed, since there is a little slippage in the torque converter (C-6 has no lock-up).

Art

 

One other way would be to get the lower gear sets for 1st and 2nd in the C-6, several outfits do make these, then go with a 4.10 ratio. Several companies also make "spliters" that mount between the trans and 'case, but with the short wheel base, the rear driveshaft ends up pointing almost straight up and down-read problems. These are very expensive also, but may compare with lower gear sets and R&P changes till everything is said and done. Might want to try TCI or another tranny rebuilder to see if they make a beefed-up AOD, again, I don't think this would be cheap, but that's the only options I can think of.

 

Higher highway speed gearing will have to be accomplished by regearing the differentials. You're right, the 460 will deliver enough power for 1st and 2nd gears but with the gear ratio you are now running you will be turning much higher rpm's in drive at highway speeds resulting in poorer fuel economy. A 460 is like a gorilla less rpm's but a lot of brute strength.

 

Have you considered larger tires? They will also help to keep the RPM's down.

 

You can Install an E4OD 1st/2nd gear set into you C-6. It will make your 1st gear 2.72 and 2nd is 1.52.

I did exactly that to my C-6 behind my 460... unfortunately.. when I fired the 460 up.. it chewed the Dist gear.. so I am waiting to fix it...

Uzi... Yamaha Sleds, Honda Bikes, and Ford Trucks....

 

with your 38" tires you should be fine i use to have a c-6 and 460 and i run 235 85 16 in the winter and 33 12.5 16.5 in the summer and i got clocked at over 85 one day while racing brother in law oops at 60 i was running about 2800 hope this helps the only other you might try is going to a 5 speed personaly i went to a 4 speed