C6 Wide Ratio Opinions

[machyoung]

Here's your proverbial "can of worms".

Who here has used a wide ratio gearset in their C6's? I have a stock 428CJ w/ a 3.25 gear and would like a little more "out of the hole". Street car only however appreciate the highway ability given the 3.25's. Don't necessarily want to increase the gear any. Would you run a stall converter? Size, stall speed?

Thoughts, comments? Thanks, Robert

[427mach1]

I would not run a different torque converter unless you have a more aggressive cam.  The entire package needs to be matched, with the cam and converter probably being the most critical.  I have never run the wide ratio gear set but that is probably your best solution unless you want to run steeper gears with a Gear Vendor overdrive unit.  I'm surprised that the 3.25 isn't working for you.  What size rear tires do you have?

[machyoung]

Will change the cam as well as the valvetrain however not going any further w/ engine modifications just yet. Has just 58k miles on it. Maybe I am a little spoiled having a couple of pretty quick cars, just needs help "out of the hole". Wheels are 14" w/ 215/70/14 BFG's.

[plovett]

I used a wide ratio C6 with 3.25 gears many years ago.   It was in '67 Cougar, approx. 3400 lbs.  I had 27" tall tires. 

I thought it worked pretty good with that rear gear.  It wasn't ideal for 1/4 mile use as I wasn't using much of 3rd gear. I had a 2800 rpm converter at the time.  It was good for crusing though.  Later I added 3.75 rear gear with the wide ratio C6 and I didn't like that combo.  It was too much 1st gear ratio. 

Later I went back to a standard ratio gearset in a C6.  It worked better with the 3.75 rear gear.   Then I went to a 4.11 rear gear, better yet. 

So for cruising or hobby use with a high (numerically low) rear gear,  I think the wide ratio gearset works well.   If I had a 2.75, 3.00, or 3.25 rear gear I would consider it.   If I had a heavy and/or relatively low powered car I would consider using it with a 3.50 rear gear.   

With lower (numerically high) rear gears I would tend to stay away from the wide ratio gearset.   Also, with a higher powered and/or lighter car, it isn't as desirable. 

Any more details on your combo?  Type of car?  Cam and rpm range?

paul

[plovett]

I see now that you have a Fairlane/Torino.  That, along with the 3.25 rear gear, would nudge me toward the wide ratio gearset.

paul

[machyoung]

Yep, 69 Cobra, bone stock 428CJ, 58k orig miles. Car is a little heavy and power seems slightly off (obviously the gears are hurting the feeling of down on power, not helping). She's a beast from 30-40 mph roll

[plovett]

Well, I think the 1st gear in the wide ratio C6 would help in your case.  In first gear, it would make it feel like you kept your current C6, but changed to a 3.59 rear gear.    The downside is bigger rpm drops between gears. 

Another thing you could do is change the rear gear to 3.50 or 3.70, but get another set of rear wheels/tires.   You could have one short set like 26" or so for around town acceleration.  Then get a taller set like 28" or so for hitting the highway.   It's not convenient unless you know you're going to be driving on the highway ahead of time, but it is simple.

paul

[Tommy-T]

The first time I ran the wide ratio C6 was with a 454 inch motor and 4.11 gears. Didn't care for it much, but it was ok.
Then I put an 8-71 blown 454 and dropped to 3.70 gears running a 33" tall tire. I liked that a lot!

In building my '65 Cyclone with a 482 inch FE, I'm going with the wide ratio again with a trans brake. 3.70 gears again and 31" tall tires.

The 6 pinion planet in the wide ratio kit is supposed to be stronger than the 3 pinion in standard C6's. And roller bearings too. I think that's a plus...except I can't seem to break a C6 and have been trying hard for many years.

[cleandan]

I am using a wide ratio gearset in my 1966 Galaxie 7-LITRE.
Slightly tuned 428 (422HP/482TQ) 3.70:1 gears, Detroit Locker, 255/60/15 rear tires, C6 trans with a 2800ish stall converter.
The combo of weight, gear, and torque work very nicely with the wide ratio gearset.

I drove the car with this engine/gear combo with the standard C6 ratios and I really like the change to the wide ratio gearset.

If anything, you won't "ruin" your car by installing the wide ratio gearset.

[Thumperbird]

I have a Broader wide ratio in my heavy 65 Thunderbird, 445, 2600 stall, 3.5 rear, 27 inch tires.
I like it, a little better off the line yet RPM's are reasonable on the highway, does not break loose as much dropping into 2nd.

[gt350hr]

  I have a wide ratio in one of my two car haulers and really like it . When I have the race car in it and all the support stuff , it moves easier than my other nearly identical F350 car hauler. Both have overdrives and 4.10 gears in the rear with 32" tall "duals".