C4, C6 Question

Dave Noll · 12-08-2014, 11:33 PM

I guess I'll start this by saying that my health is a limiting issue on doing heavy work on my car. That said, given one of each transmission comparibly prepared with similar convertors, EXCEPT, the C6 has a 2.75 gearset in it & my car is still a little light for "N". (the car 72 Cougar 351C 2BBL that has yet to touch its index) Opinion's ?

7423 · 12-09-2014, 12:56 AM

Without a doubt, the C4 is the better choice. Lighter, faster, cheaper, more room for headers. With a 2.91 low gear set, that 2V Cleveland will be very happy.

Dave Noll · 12-09-2014, 02:18 AM

How well do those 2.92 gear sets hold up ? I killed one of the stock 3 gear planets in my last C4. My headers will clear a C6, now..

vic guilmino · 12-09-2014, 08:05 AM

get a pro trans gear set for the c-4

Jim Caughlin · 12-09-2014, 12:12 PM

AS few years back, we swapped from a C6 to a C4 in a 2900# bracket car, small block, both trans were 8" converter, no trans brake. It went .25 quicker. Wasn't a perfect back to back test but pretty close. I have no question that there would be significant improvement switching to the C4. Lots of good parts for C4's these days, no reason for strength issues to be a problem.

Dave Noll · 12-12-2014, 03:07 AM

C4 it is,Thanks Guys. Guess I better get to selling some stuff to get one of those gearsets.

SSDiv6 · 12-12-2014, 10:23 AM

Quote:

Originally Posted by Dave Noll

C4 it is,Thanks Guys. Guess I better get to selling some stuff to get one of those gearsets.

Talk to Brian Thompson, I believe he runs a Broader C-4 with a low gear.

fordteacherguy · 12-13-2014, 09:15 PM

I run a Broader 2.92 set and also have a ATI 2.92 set C-4. The Broader set looks more robust than my ATI set and held up for about 3 years of hard abuse before it looked like it needed rebuilding. The actual planetary is from a 125C GM, so I just rebuilt it using those parts every few years. But last I heard that set may or may not be available, check Broader Performance website. Good guys.
Where the Broader stuff uses Ford hubs and GM gear sets the ATI uses GM hubs with Ford splines pressed and welded in and just gives you GM clutches to make it work in a C-4.
I haven't used my ATI set yet but, it looks like it will hold up ok. Wasn't as impressed with what I got vs the Broader set up. With all of the C-4's the front planetary is the weak point usually with thrust washer wear on the side of the planet pinions. There are limited manufacturers of the 2.92 sets for C-4 and I haven't seen a 6 pinions 2.92 set yet. If you can find ones with Torrington bearings on the planet pinions even better. Maybe some others can chime in.

Dave Noll · 12-14-2014, 03:59 AM

Well since it came up, I'm real curious how you rebuild those. I just checked Broader, they still show one. What about the ACT Automatics unit ? All I see on ATI is for the 6 pinion stock ratio & the low drag piece.

EDIT: Okay i can how to rebuild the stock piece if I had a Bridgeport still available to me, BUT ........ Is that GM piece the same way ?

jmantle · 12-16-2014, 10:44 PM

Quote:

Originally Posted by Dave Noll

Well since it came up, I'm real curious how you rebuild those. I just checked Broader, they still show one. What about the ACT Automatics unit ? All I see on ATI is for the 6 pinion stock ratio & the low drag piece.

EDIT: Okay i can how to rebuild the stock piece if I had a Bridgeport still available to me, BUT ........ Is that GM piece the same way ?

If your looking for an inexpensive way out and don't mind running the stock ratio, the early 64 -66 C4's had a brass and steel washer at each side of the planet gears and would stand up much longer than the steel washer only later sets.

Jim Mantle V/SA 6632

12-08-2014, 11:33 PM	#1
Dave Noll Senior Member Join Date: Nov 2007 Location: Div. 6, Eastern, WA Posts: 694 Likes: 2,255 Liked 219 Times in 105 Posts	C4, C6 Question I guess I'll start this by saying that my health is a limiting issue on doing heavy work on my car. That said, given one of each transmission comparibly prepared with similar convertors, EXCEPT, the C6 has a 2.75 gearset in it & my car is still a little light for "N". (the car 72 Cougar 351C 2BBL that has yet to touch its index) Opinion's ? __________________ Dave Noll, E/FS ,L/SA 6526

12-09-2014, 12:56 AM	#2
7423 Senior Member Join Date: Dec 2006 Posts: 640 Likes: 0 Liked 1 Time in 1 Post	Re: C4, C6 Question Without a doubt, the C4 is the better choice. Lighter, faster, cheaper, more room for headers. With a 2.91 low gear set, that 2V Cleveland will be very happy.

12-09-2014, 02:18 AM	#3
Dave Noll Senior Member Join Date: Nov 2007 Location: Div. 6, Eastern, WA Posts: 694 Likes: 2,255 Liked 219 Times in 105 Posts	Re: C4, C6 Question How well do those 2.92 gear sets hold up ? I killed one of the stock 3 gear planets in my last C4. My headers will clear a C6, now.. __________________ Dave Noll, E/FS ,L/SA 6526

12-09-2014, 08:05 AM	#4
vic guilmino Senior Member Join Date: Dec 2001 Location: wv Posts: 881 Likes: 42 Liked 56 Times in 21 Posts	Re: C4, C6 Question get a pro trans gear set for the c-4 __________________ Vic Guilmino 1129 STK

12-09-2014, 12:12 PM	#5
Jim Caughlin Senior Member Join Date: Mar 2002 Location: Woodburn, Or Posts: 635 Likes: 70 Liked 693 Times in 208 Posts	Re: C4, C6 Question AS few years back, we swapped from a C6 to a C4 in a 2900# bracket car, small block, both trans were 8" converter, no trans brake. It went .25 quicker. Wasn't a perfect back to back test but pretty close. I have no question that there would be significant improvement switching to the C4. Lots of good parts for C4's these days, no reason for strength issues to be a problem.

12-12-2014, 03:07 AM	#6
Dave Noll Senior Member Join Date: Nov 2007 Location: Div. 6, Eastern, WA Posts: 694 Likes: 2,255 Liked 219 Times in 105 Posts	Re: C4, C6 Question C4 it is,Thanks Guys. Guess I better get to selling some stuff to get one of those gearsets. __________________ Dave Noll, E/FS ,L/SA 6526 Last edited by Dave Noll; 12-12-2014 at 03:33 AM.

12-13-2014, 09:15 PM	#8
fordteacherguy Member Join Date: Jun 2007 Location: Federal Way, WA Posts: 233 Likes: 24 Liked 147 Times in 47 Posts	Re: C4, C6 Question I run a Broader 2.92 set and also have a ATI 2.92 set C-4. The Broader set looks more robust than my ATI set and held up for about 3 years of hard abuse before it looked like it needed rebuilding. The actual planetary is from a 125C GM, so I just rebuilt it using those parts every few years. But last I heard that set may or may not be available, check Broader Performance website. Good guys. Where the Broader stuff uses Ford hubs and GM gear sets the ATI uses GM hubs with Ford splines pressed and welded in and just gives you GM clutches to make it work in a C-4. I haven't used my ATI set yet but, it looks like it will hold up ok. Wasn't as impressed with what I got vs the Broader set up. With all of the C-4's the front planetary is the weak point usually with thrust washer wear on the side of the planet pinions. There are limited manufacturers of the 2.92 sets for C-4 and I haven't seen a 6 pinions 2.92 set yet. If you can find ones with Torrington bearings on the planet pinions even better. Maybe some others can chime in. __________________ Brian Thompson NHRA Stock / Super Stock Class P/SA 6665 SS/MA 6665 Last edited by fordteacherguy; 12-13-2014 at 09:17 PM. Reason: Spelling

12-14-2014, 03:59 AM	#9
Dave Noll Senior Member Join Date: Nov 2007 Location: Div. 6, Eastern, WA Posts: 694 Likes: 2,255 Liked 219 Times in 105 Posts	Re: C4, C6 Question Well since it came up, I'm real curious how you rebuild those. I just checked Broader, they still show one. What about the ACT Automatics unit ? All I see on ATI is for the 6 pinion stock ratio & the low drag piece. EDIT: Okay i can how to rebuild the stock piece if I had a Bridgeport still available to me, BUT ........ Is that GM piece the same way ? __________________ Dave Noll, E/FS ,L/SA 6526 Last edited by Dave Noll; 12-14-2014 at 04:19 AM.