[shagginwagon]

my stock 4l60e cant have long left... im debating on whether to replace it with another 4l60e with a good torque converter and do gears at the same time, or to swap a th350 in it with a good converter and keep my 2.93 gears .... i have 95 b body with an lt1 and stock cam and 27in tall tires

 

[KW Baraka]

my stock 4l60e cant have long left... im debating on whether to replace it with another 4l60e with a good torque converter and do gears at the same time, or to swap a th350 in it with a good converter and keep my 2.93 gears .... i have 95 b body with an lt1 and stock cam and 27in tall tires

1. TH350 = HUGE step backwards.....don't do it! it's not stronger than a 4L60E and there's all sorts of computer considerations with the swap. If you must go with an old-school tranny......go with a TH400; at least it's a stronger unit. But.....if I were in your position (and I have been), I'd have the 4L60E rebuilt!

2. Gears? Do 3.73's or don't bother! OK.....3.42's would be a nice step up for you, but IMO, the Impalas should've come stock with 3.73 gears (Yeah.....I know yours is a Caprice ) But the bottom line is B-bodies LOVE gear......and your 2.93's are strictly for HWY gas mileage. On the whole, the 3.73's won't effect gas mileage much because what you'll lose in HWY MPG, you'll almost make up in city MPG (yep....3.73's will get better city MPG than the 2.93's ).

3. TC? Go with a 2800 stall Yank or Vigilanti......you'll want a 9.5" TC in any case. Going with a lower stall TC (2000 to 2600) will mean going with a 10"+ TC.....and those just don't take care of buisiness if you're really looking for a performance upgrade. A 2800 stall TC is the lowest stall you'll get with a 9.5" unit......and works great with a stock(ish) motor.

4. BTW.....one you have this work done, you'll need to have your PCM reflashed for the gears and TC. I use www.pcmforless.com.

You have PM, BTW......

KW

 

[shagginwagon]

THANK YOU! only reason i said th350 is bc i have 2 good built ones here with long tail shaft (i am manager at an all chevy salvage yard) and one has a 2800 converter and other has a 3500...

i also have a spare low milage 4l60e out of a 95 9c1 here waiting for a good converter and about the gears, i really didnt know that, i was considering 3.73s or 3.42s just bc i have alot of them here out of chevy trucks (my car has an 8.5)

the only reason i considered a th350 is bc several of my f body buddys have went that round and made up for having such a high first gear with the right converter, but all of them have 3800-4200 converters, i could live without overdrive but theres no way in hell i could drive this thing with such a loose converter in it

so if i go with the 4l60e you say i should use a 28-3000 stall? does that get it right in the prime rpm range for a stock cam? oh, and its a roadmaster wagon, and ill check my pm

 

[shagginwagon]

thank you for the reply and input btw

 

[KW Baraka]

.......so if i go with the 4l60e you say i should use a 28-3000 stall? does that get it right in the prime rpm range for a stock cam? oh, and its a roadmaster wagon, and ill check my pm

The meat of a stock B-body torque curve is right about 3000 RPMs.

Ideally, you want to be just below that with your torque converter's stall rating. That way, if you're racing, and the tranny shifts, yo so not go much below peak torque RPMs on that upshift.....and your acceleration continues to progress .

Additionally, your wagon weighs what? About 4500-4600 LBs? Yeah.....just like those Chevy trucks, you're gonna want some gear. As stated.....3.73's would probably be the most satisfying!

And.......happy to help!!!!

KW

 

[Racy Roadmaster]

KW- You mentioned that if you changed your rear gear ratio you would have to have your PMC reflashed to match the new gear ratio. I have a 96 B body wagon that currently has a 2.56:1 rear gear,I have a 3.31 or there abouts complete wagon rear end assembly that I plan to put in the car this summer.It sounds from your experience that may not be enough gear to make a difference.WHEN I CHANGE TO THE LOWER GEAR WILL I NEED TO REFLASH MY PCM? Also for the guy with the 95 B body wanting to change transmissions, be careful from what I understand you should only use the exact year transmission for your year car,even though they will bolt up the 96 transmissions have one more servo or selenoid in them that causes havock if you put them in an earlier year car. I know because I have just been thru this a few months ago. ed
PS- I HOPE THIS ISNT CONSIDERED HIJACKING THE THREAD, I BELIEVE I
AM STAYING WITHIN THE LIMITS OF THE ORIGIONAL THREAD.

 

[shagginwagon]

racy roadmaster, i know that a 95 is one year only on the 4l60e and that is the exact year i have stashed back for mine, when i was debating on the th350 it would have no electronics going to it, and as for your gear ratio, you would have to get your pcm reflashed bc your speedometer would be wrong and it would mess with the way it shifts, ive run into that before even while changing around tire sizes

and what year is your rear end out of? the only ratio gm ever put in lt1 wagons was 2.73 in the non tow pack cars and 2.93 in the tow pack cars, i know they put 2.56s in alot of the tbi sedans years earlier but of all of them i have dismantled i havent came across that ration in a wagon, and the closest thing i can think of to a 3.31 ratio that gm put in anything was a 3.42 which is also very rare in a 91-up b body

 

[Racy Roadmaster]

Shagginwagon, Thanks for the reply, The differential that I got was from a
91or 92 Oldsmobile B body wagon, I forget the name of the olds model but its from an olds wagon,I believe it had a tow package,it also has a posi style carrier. ed

 

[KW Baraka]

Shagginwagon, Thanks for the reply, The differential that I got was from a
91or 92 Oldsmobile B body wagon, I forget the name of the olds model but its from an olds wagon,I believe it had a tow package,it also has a posi style carrier. ed

Olds Custom Cruiser.

You will notice a difference with the 3.31 gears (I don't think that's the correct gear, though) from the 2.56 gears, but I wouldn't call it a significant upgrade.

But hell.....if that's what you got.....go for it!

And yes.....you can go to www.pcmforless .com also to get a new chip burned.

KW