I am insane (or stupid), now here's the question:

Can you swap a good 13BT manual transmission onto the end of a 20B? Save getting a better flywheel, balance, and clutch and all, you think it would work? (and by work I mean actually be safe and functional). Thanks!

 

yes

 

Save for a few bolt holes (2 if I remember correctly) The FD stock tranny will bolt up to a 20b.

 

the 13b tranny bolts right up to the 20b, but if your going to use the 20b to its full power potential it wont last very long, the 13b tranny sucks, I would go with a custom bell housing and find a 6 speed t56 tranny, thats probably one of the cheapest routes if you want something to last. A lot of guys are going with aftermarket trannys like liberty or guru, but there big money. If your swapping a 20b with modest power and you decide to go with the 13b tranny, atleast upgrade the clutch and flywheel.

 

Any ballpark prices on a t56 - 20b bellhousing? I should be able to get a good deal on a slightly upgraded t56 w/steel shift forks. Then probably go with a Spec 3i clutch or something. Just gotta see how much damage ($$) it will do.

 

I have been reading that the t56 tranny doesnt like huge tq numbers either
500+

 

i thought it was around 2500 for a built t56 and custom bellhousing

 

I'd rather just buy 10 used Turbo II trannys and keep swapping them for that price.


-Ted

 

I talked to several reputable shops about using a t56 for my project. The problem is the syncros are not designed for high rpm use. The exception to the rule is theh M6 and M12 setup in the Corvettes. I also believe the m12 gearset comes in the CTS-V and possibly the Pontiac GTO boxes.

 

this is a good info site
http://www.5speedtransmissions.com/6_speed.html

there is a link that shows a viper ran a 9.9 with a t56
well we have guys running 8's on t2 boxes...

a 6 speed would be nice but it makes you wonder if it would hold the power.
time to research the vette boards

 

Karl Martin, (the guy that rebuilt my 3-rotor) has a 800rwhp drag car and he's using a cryo'd FD tranny for years.
300below.com will treat your parts for $3.50/lb.
This is the route i'm going to go.

 

I thought the vet had a transaxle like a porsche? Although a custom transaxle in a FD would be sweet.

 

the new vettes are transaxle
there was a guy who did a transaxle fd already.

 

Awhile back someone on the forum was working on it. I later found out that he bought the gearbox, sized it up, realized it would take a lot of cutting to make it fit, and that was the end of the project. To my knowledge nobody has done it.

I have probably killed about 20hrs over the last 2 years looking into doing it. I think it's a great idea for a lot of reasons. However, it is a big gearbox, and everybody who has looked at it for me, and the other guy, are not sure it will fit due to the length and width. If you are over 6ft forget about it, because the tunnel has to be widened near the storage bins to accommodate the gearbox width and will interfere with the seat travel.

At the very least the transmission tunnel, rear subframe, 1/2 shafts, driveshaft, torque tube, shifter linkage, bell housing, input shaft, and exhaust system will have to be modified.
You can't just use a stock vette box and dif either because of the gearing. For it to really be effective you need to change the final drive ratio and the double gear set at the back of the transmission. All said and done it's a $7,000-$9,000 project imo.

 

61620B (Rene) has been running an FD tranny in his 20B for years and has had no problems.

 

To answer the original poster's question: I have an '87 T-II gearbox in my car. In fact, everything from the flywheel back is T-II.

Someone commented that the T-II wouldn't last. I have over 70,000 miles on mine with no problems at all. FWIW, I don't do drag racing, so the abuse factor is low.