If it were me, I would go with the tb modified stall from Circle D at 3k, and then decide if you need 4.10's. If your gonna be towing, let them know so they can make it a little tighter for you. That will also help with dd'ing. I love the rpm's my 3.73's run at on the highway, I dont think I'd be happy with 4.10's cruising at 80mph.

 

First off, welcome to PT! A CC is a lot of weight to push. Anyway, I know u like your 22", but they aren't doin ya any favors in the getty-up dept. Yes, u have a 3.73 Posi.

Billy, 2.5 60'?!?

Peach, I think he's givin some great advice on the "balance" thing.

eatapeach on a 31.5" tall, in order to figure out what RPM's u would be spinning w/. 4.10s vs the 3.73s that u have, I forgot exactly how to figure it, but u wouldn't be > 450 RPMs. I know that's kinda vague, but on a taller tire, it's not too big a difference. On shorter tires, it's of greater difference.

 

I changed over from 373's to 410's 2 months ago and it made a big diff. with the low end, At 75 mph RPM's are at 2400 w/31in tire in OD.. not a problem, I think its the perfect gear for this truck, I want to install a tbss converter to help a little more...

 

I am also interested in a TC change. Could someone please explain how a 2800 or a 3200 stall is different from stock? Pros and cons. I tow a good bit of weight so I do not want to endanger my trans with the higher heat a new TC can make.

I also like the 3.73 on the highway but the 4.10s really help with the takeoff and towing capacity.

 

I'll explain it best I can, tho someone may do a better job.
1st, stock TC is ~1600 RPMs. Not the 28-3200 u mentioned. When u mash a stocker it goes or "flashes" to 1600, the modded one "flashes" to what was spec'd. It multiplies the torque, & keeps the shift extensions to smaller amounts. You know how when u give it gas, say on the 1-2 shift. The amount it falls back or down is / are shift extensions. By not droppin as much, u keep it in the powerband.

OH IDK if u have a stock trans cooler, but if ya tow, & do not have 1, get 1!! Even on a stock stall. A $100-140 cooler (or less on smaller ones) is just cheap insurance to extending your tranny's life. A trans temp gauge would be a help too. How much wtg. are u towing?

Pros:They're fun, esp. off idle. I couldn't imagine what a bigger stall would do for the fun factor. Many get better times.
Some say better MPG (see cons on this too).
Cons:Ya gotta remove trans to do, can use more gas (stall speed dependent & your foot), lockup may take gettin used to, & good ones don't come cheap. Or ya, may have to tune or not, stall speed affects this too.

 

Thanx a lot! I have a 2500 so it comes with a trans cooler stock. I have been considering investing in a larger one, just dont know where to find a good one. Does the 3500s have larger coolers? I tow everywhere from 2k to about 15-16k lbs. I beat on this truck at times.

It would seem a mild TC could help with low speed take off and towing cuz it wouldnt have to work as hard to get back to higher rpms. Am I wrong? I have seen fellas on here saying there trans can get up to 280+ degrees, I definatly dont need that. I have never seen mine get over 190.

Thanx again!!

 

One minor correction: the stock stall speed in the 4L60E trucks is 1800rpm. The diesel HDs have a 1600rpm TC as does all engines with the 6L80/6L90 transmissions, while the 4.2L TB/envoy stalls at 2400 and those with envoy denalis (5.3) who swapped in the 4.2's TC stall around 26-2700 and should be the same in the 5.3L 4L60E trucks.

If you do a lot of towing, stick with a 12" TC or get a 10" with multiple TCC clutches. Beyond the difference in friction area between a single 12" lock up clutch and a single 10", the 12" has a longer leverage arm on the axis of rotation which is a much bigger advantage than most realize. I'd guess a 10" with two lock up clutches should be as strong if not a little stronger than the single 12" clutch. I can't recommend a specific brand or model since I tow a lot and haven't researched it much... I like having the stock TC for what I do. I'll be eventually going 4L80E with a twin-screw supercharger so bottom end won't matter much given the boost a positive-displacement blower makes at low rpm.

Bow-Tie: you shouldn't need a lot of stall since the 6L90's have a brutal 1st gear and tight spacing between all gears. I personally wouldn't go over 2500 on the stall speed given your situation. YMMV

 

A good way to help understand how a stall acts is to get on youtube and watch videos of trucks with different sized stalls and how they drive. If you tow that often, you need to invest in a tru-cool 40,000 regardless. I think their under $100 on ebay.

 

Thanks fellas for all the clarification. I am going to do alot of research before choosing a TC. If I have a 1600 stock stall now, I'm assuming a 2000 or 2200 stall would be just about right.

Is true-cool trans coolers good quality? If I change the stock cooler, will the new one void my warrenty on the trans? I only have 13500+ miles on this truck and have alot of warrenty life left.

Thanks again fellas, lots of good information here.

 

I would go for the 2200 if your looking at thoughs two. For the same money and you be happier with that little bit extra.