hey guys, I currently have a 1986 iroc, with a 305 and a 700r4... Im wanting to swap both eventualy, but for now im just going to do the trans. I would really like a 6 speed, but one that will be able to be used with my 305, and also later with an Lsx... I know the 305 doesnt have enough power to be in 6th gear all day, if at all, but what should i do to my 305 in the meantime? it does need a tune up, but anything else i should do while i have that done? but back to the trans; what donor car should i look for? and can i use a console from a 3rd or 4th gen? or will i have to cut and fab it myself? and what ALL parts should i get from the donor? all answeres are very much apreciated, thanks!

 

"my t-56 swap thread" At the top. Read it.

 

what exactly are you wanting me to read? Im new to forums like this so im not sure what to look for.


ok, i thought you were saying read it at the top, not the THREAD at the top, my bad. Im working on it

 

stay away from the 1993 six speed.the later ones have a higher overdrive.....50.

 

thats what ive read, they are also weaker, but i was wanting a tranny compatable with the engine i have now, and later for when I get an Lsx.

 

the key here is "later used for LSx swap" basically you need the t-56 that came stock behind the LT motors to use with your 305. however you cant run that trans behind the LSx motor without modification. The LS t-56 uses a longer input shaft and has 1 less bolt on the bellhousing.

 

I see... so should I use an ls t-56 now and just mod it to fit my engine?
or buy a t-5... haha

 

you can make a LSx t-56 work behind a 305, Ive done it. However its going to cost more in the long run because youll have to buy swap parts now and different swap parts when you go LSx. You just wont have to buy another trans.

 

Also, check out this thread I created:

https://www.thirdgen.org/forums/tran...-overview.html

 

Thats great info for the LT t-56 swap, which wont work with a LSx motor.

 

Yep, but a lot is still relevant. Only difference would be the bellhousing/clutch considerations if using an LS T56 with a SBC/BBC. Mounting, electrical, shifter, crossmember, ect all the same for both.

 

Actually to use a LS t56 on a gen 1 SBC, you have to use an adapter plate or a conversion bellhousing. either way, it pushes the trans further back (to accommodate the longer input shaft) so the xmember has to be set further back, the drive shaft has to be shorter. so the LT t56 swap parts dont work on an LS t56 behind a gen 1 SBC

 

And not to mention the LS t56 uses a hydraulic TO bearing, so the hydraulics arent the same.

 

Good call with the crossmember and driveshaft. Just forgot.

 

I was thinking more about mounting to the firewall which is the same, but yes completely different hydraulics.

 

I personally use the t-5 bell, clutch and hydrualics (just because my car came stock with the t-5). I just run the adapter plate to bolt the LS t-56 to it. But for the OP, hes switching from an auto, so that option doesnt make much sense.

The OP has a few options.
#1 buy everything to swap in the LT t-56 now and buy everything for the LS t56 when swapping to the LS motor.
#2 buy everything to swap the LT t-56 now and swap to a gen1 SBC later instead of LSx (no need to replace any part of the trans swap).
#3 buy everything to swap to a t-5 now and buy everything for the LS t56 when swapping in the LS motor
#4 leave the auto in and swap to an LSx motor and LS t56 later.

 

so what would you suggest?

 

If youre dead set on the LSx motor, id suggest wait and swap the motor and trans at once.
If you are open to staying with a gen1 SBC, id suggest just doing the LT t56 now. Itll bolt up right to the new motor.

 

the Lt1 t-56 will bolt to the Lsx? or am I reading it wrong?
and what mods will need to be taken in order to get an Lt1 t-56 behind me engine? I am also considering getting a t5 and just waiting to find an ls and the trans together

 

The LT1 T56 will NOT bolt to an LS engine, but WILL bolt to any SBC/BBC. So putting an LT1 T56 in your car not is a direct bolt-on. You'd still have to find a pile of parts to do the swap. The other option is to go with an LS T56 now, buy the adapter bellhousing, then you'll be able to use it when you do an LS engine swap. The things you're talking about aren't cheap though.

 

The conversion bellhousing will allow an LS t56 to bolt to a gen 1 SBC. however you cant reuse that bellhousing on the LSx motor. the input shaft of the trans would be too far back for it to mate to the LSx motor.

If you do use the conversion bellhousing now, you will need the LS t56, the conversion bellhousing, pedals, clutch, flywheel, and hyraulics from a 3rd gen fbody, a new ls t-56 swap xmember (spohn makes them, i have one with the xmember mounted tq arm), and you will have to cut your drive shaft 2" shorter. And if you dont get a xmember mounted tq arm specific for the LS t56 swap, youll have to cut yours down 2" to mate to the mount on the trans.

When you swap to an LSx motor, you will need to replace the conversion bellhousing for an Ls bellhousing, the clutch, flywheel, pedals, and hydralics from a LS 4th gen fbody, another new xmember, and a new drive shaft (since the one you cut 2" short will be too short now). and if you dont go with a xmember with a mounted tq specific to that xmember, youll need a new tq arm again (since again the one you cut down 2" shorter will be 2" too short now).

 

to get an LT t56 behind your 305, all you need is the pedals, clutch, flywheel, and bellhousing and trans from a LT 4th gen fbody. youll need a t-56 swap xmember (again spohn sells them along with other places, or you can make your own) the tq arm you have now will bolt to the tq arm mount on the trans, no mods needed. you will also need to swap to an electric speedo (if yours is mech) or have the t56 tail housing machined for a mech speedo (youll have to do this no matter if its LS or LT t56)

and if you dont swap in an LSx motor and stay gen 1 SBC, all this will work with the new motor.

 

The difference in length between the LT and LS T56 is only 5.". That difference comes from the bellhousings having a depth of 4.9" for the LT and 5.5" for the LS. I'm using a LS t56 behind a sbc. I had the input shaft shortened .5" and i'm using Quicktime 8020 bellhousing, with sbc flywheel and clutch.

 

alright... you guys are quite informative... haha, and Im very thankfull for all your info. so should I try to find a totaled ls car in a junkyard with a working trans and use all it's parts for a swap now? I mean when I pull the trans out, the engine is comming out also. so I plan to rebuild it and mod it just a touch. but yeah, find a junked ls? or would you guys think its easier on me (and my wallet) to get a 3rd gen's t5 for now? once I get my 305 rebuilt and running nicely, Ill be fine with it for a while, so im not in a hurry to get an ls and all the stuff for it. it can wait a while.

 

Itll be cheaper to go with the t5. Geting a junkyard ls1 with t56 together isnt gonna be cheap. In general LS swaps arent cheap, you might wanna cruise the LSx swap forum to get an idea of how much is really involved with it.

 

alright. I believe i may just do the t5 conversion for now. how much should i expect to buy one for? and how much should i sell my 700r4 for? haha, thanks

 

good working 700r4 would be about $100-$300, depending on milage. A good used t-5 can be had for $500 for a complete swap (or atleast close to it) setup. they pop up in the classifieds on here from time to time. just for pricing info on the possible LSxswap, theres a wrecked 2000 camaro with 168k miles on the local CL, they want $2000 for it, but its got a running LS1 and t56.

 

ooooo, where is that ad? and what is the location of your "local"?

 

DFW Texas. Even as a 168k mile car, its still a hell of a deal.

 

 

dang it... Im in NC... Id jump on that... but thats a bit out of my way... lol... could you pm me the ad link tho?

 

already beat you to the punch on that one

 

send me the $2000 and ill go buy it and send you the motor and trans

 

almost would, but id love to use alot of the interior parts and such in my car, if it really is the good deal it seems to be, ill go trailor it up! haha

 

thats what i want out of it...all leather int

 

yeah... i eventualy want that also... 3rd gen body on an ls everything else...

 

If you're going to do a 2.66 / .50 geared T56 w/ the LS_ engine,

do a 3.73 or higher rear first. Then the T56 won't have poor drivability w/ the 305 if you do that swap before the engine.

(even w/ 3.73 drivability isn't great w/ 305 & 2.66 T56 but a compromise rear that will work perfectly w/ the LS_ / T56 later makes a lot of sense to do first.)