4+3 substitute??

[WhalePirot]

I am starting to think about changing out my 4+3 with either a six speed automatic or manual. I would prefer a paddle shifted automatic and was advised today that the Tremec is superior to the Richmond, being smoother and stronger. I also heard that a place in Arizona mods a Tremec for $2500; making it a paddle shifter.

I need power capabilities of 600/600 or more.

 

[c4cruiser]

You might try Keisler Engineering www.keislerauto.com . They have a C4 replacement tranny that is supposed to handle high HP motors. Think they have both 5 and 6 speed versions that use the OEM shifter location.
The Richmond Gear tranny for Vettes is also a bolt-in (like Keisler, they have holes in the tailshaft for the C-beam) and they are very stout trannies.

In either case, you should probably call them and ask what they recommend for 600+HP applications.

 

[KANE]

I am starting to think about changing out my 4+3 with either a six speed automatic or manual. I would prefer a paddle shifted automatic and was advised today that the Tremec is superior to the Richmond, being smoother and stronger. I also heard that a place in Arizona mods a Tremec for $2500; making it a paddle shifter.

I need power capabilities of 600/600 or more.

ROD. Richmond Overdrive 6 speed.

If I am correct, you can get it as either one of these-
1-2-3-4-5 and 6 is OD
1-2-3-4 and 5/6 are ODs

I think ROD have the most flexability. You can get a seriously low first in a custom close ratio tranny. Then, you will smoke McLarens, DB7s, and even a Diablo.

 

[Ken]

You can get a seriously low first in a custom close ratio tranny.

Mine's off-the-shelf at 3.28:1 and coupled with a 3.73:1 rear, I go through it real quick! :eek

 

[G Winter]

My 90 I believe has 4:10 gears with the 6 speed which you probably know is 5th and 6th overdrive. I find myself going for second gear really quick and second is plenty quick to the 5500 rpm also. Almost seems to be to close a ratio in the first two gears. I haven't taken it to the track yet, 95 in forth gear is 5500 rpm. Seems that could put me out of rpm before the end of the quarter mile in forth gear. Going for 5th in doesn't seem to be a good option. Depending on the rpm you run I would really consider how that plays out.

 

[WhalePirot]

Thanks. Been looking at Tremecs and the Richie. I hear there is a price increase coming in January. I like the bolt-in offered by Keisler; minimal cutting and all. Lord knows, I've done my share of modding and am looking at hood and nose changes for cold air in- hot air out.

I like the six speed double overdrive idea. With all the torque in this 406 I smoke the rears quite easily with the 3.54 rear, so I don't need a super low 1st gear. I love full throttle dashes to cruising speed, then punching the cruise control and chillin'; the MaxiMouse motor loafing at sub2k. A .50 final O/D is a great idea and should make this antique capable of 200mph+. I've never been past 160 in any car; one my modded '71 LS-6; the other a Viper. (Those damn hard saddle bags on the Beemer hold my R1100RS to 140; fuel shutoff was at 137 on the 740i.)

NE one know where to $teal either of these trannies?

I don't think there is really anything wrong with this 4+3, (totally redone and strengthened) but I like simplicity and more torque 'headroom' than it affords.

 

[Ken]

... minimal cutting and all.

No matter how you look at it Mike, you're gonna have to cut the floor (tunnel). The factory shifter mounts to the floor and not the transmission; you'll have to open the hole for the shifter the transmission will use.

 

[johnny80]

I am going thru the same issue. I know that its gonna take some work to replace the 4+3 but it will be well worth it! Good luck