t-5 to t-56 swap

[QuasarBlue95]

would this be feasible? i'd sure love the extra gear! the v6 and v8 probably don't share a bolt pattern, though.

[navyblue2000]

the stock V6 coudln't handle 6th gear. you'd need to be up around 300ft/lbs peak for 6th gear to not completely bog the engine

[Dominic]

bs! [img]graemlins/bs.gif[/img] The Grand Prix GT runs at 2000RPM ~80mph in final gear.

With 3.42's in the back, that means your OD could be 0.65 or so and you'd be fine. The tremec comes with a 0.5-OD or a 0.62-OD... the 0.62 would be awesome for hwy cruising!

[navyblue2000]

there's a difference between FWD OD and RWD 6spd. gotta figure in the rear end gearing...i think?

[Jason3.4L]

<blockquote>quote:</font><hr>Originally posted by navyblue2000:
there's a difference between FWD OD and RWD 6spd. gotta figure in the rear end gearing...i think?<hr></blockquote>

FWD has the same except instead of being in the rear end, they have them where the half-shafts go into the tranny.

[prdcp97v6]

How much gas mileage do you need, since the ratios for 5 speed and 6 speed except for the 2nd .6 overdrive in the 6 speed?

[Deuce Bigs]

i've been kinda looking into this and one thing is you'll most likely have to use an LT1's t56. the LS1 t56 is different.

[QuasarBlue95]

so an lt1 has the same bolt pattern as the 3.4? and the 3.8?

[LotsaSpeed]

now I know stock v6 can't handle 6th gear, but what about if I put a super or turbo on my 6, then it should be able to handle the 6th gear, right.

[hockeyman]

Hey wilsoncj6, if you do this project, and everything bolts-up, PLEASE e-mail me!!! I've been considering doing this project for quite some time now, but never got around to asking about it. Thanx, Marc

[QuasarBlue95]

there is a t-56 for sale in the thifty nickel for $700. don't know what kinda shape it's in or that's a good deal, but that's what got me thinking. being a manual, i wouldn't think there would be any computer problems with the swap. as long as it bolt pattern is the same it should be an easy swap. should be same length, etc. i think a v6 with intake/exhaust mods would be able to handle 6th easy. i know there are lots of times i want to shift into 6th on mine and i'm just a 3.4! if know one on here knows, might check with a chevy mechanic about the bolt pattern. humm.... this mod would quickly be followed by new gears, too!!! [img]graemlins/burnout.gif[/img]

[viper98885]

I have been doing some research on this because it is something that I am definitely going to do. I am upgrading to 4.10 gears and doing the T-56 conversion but I am wondering if any of you have some answers to my questions:
1- According to GM, the input shaft has a different part number from the 94-97 T56 (12523215) and the 98-02 T56 (12453260). According to Centerforce's website, both have a 1-1/8" diameter X 26-spline input shaft. Does anyone know if Centerforce's information is correct.

2- The tail extension on the T56 is different between the 94-97 and the 98-02 T56's. Will this change the angle that the shifter sits on top of the transmission between the years.

The main casing is the same throughout the 93-02 period which is the part that bolts to the adapter plate so I am not worried about that.

Any help would be great. I have a available locally that I would like to go ahead and pick up if I know it will work. Worse comes to worse, I will meet up with the seller and see if one of my clutch discs that I have laying around here will fit the input shaft.

Thanks!

[boosted thrills]

<blockquote>quote:</font><hr>Originally posted by viper98885:
I have been doing some research on this because it is something that I am definitely going to do. I am upgrading to 4.10 gears and doing the T-56 conversion but I am wondering if any of you have some answers to my questions:
1- According to GM, the input shaft has a different part number from the 94-97 T56 (12523215) and the 98-02 T56 (12453260). According to Centerforce's website, both have a 1-1/8" diameter X 26-spline input shaft. Does anyone know if Centerforce's information is correct.

2- The tail extension on the T56 is different between the 94-97 and the 98-02 T56's. Will this change the angle that the shifter sits on top of the transmission between the years.

The main casing is the same throughout the 93-02 period which is the part that bolts to the adapter plate so I am not worried about that.

Any help would be great. I have a available locally that I would like to go ahead and pick up if I know it will work. Worse comes to worse, I will meet up with the seller and see if one of my clutch discs that I have laying around here will fit the input shaft.

Thanks!<hr></blockquote>


i was kind of looking into what is needed to do the t-56 behind my friends 3.4L s-10, looks like the '98-up ls1 trans will work the best becaise the input shaft is 7/16 longer than the LT1 input so make a spacer that is 1/2 thick to adapt the t-56 to your current bellhousing and your current clutch setup should work, i do need to know the length if the t-5 input shaft though.

IMO id go with atleast 4.56 geras or even 4.88 if those are available for the 7-5/8 rear.

someone send my a T-56, i will make it work

[lord_gufi]

why dont you try using the t56 with the same bolt pattern as the t-5... its built for gm vehicles with a t-5 ~grabs url~
http://www.standardtransmission.com/BW_T-56.html

there ya go boys and girls, it aint cheap but it exists!

[viper98885]

<blockquote>quote:</font><hr>Originally posted by lord_gufi:
why dont you try using the t56 with the same bolt pattern as the t-5... its built for gm vehicles with a t-5 ~grabs url~
http://www.standardtransmission.com/BW_T-56.html

there ya go boys and girls, it aint cheap but it exists!<hr></blockquote>

Because it is MUCH cheaper to go with the adapter plate that Sallee Chevrolet offers and a used T56. I have a guy locally selling me his T56 for $900. I don't think I could justify spending another $1500 for the T56 with the T5 bolt pattern.