LT1 T-56 bought now need to intall and have ???

[superwade57]

hey guys i bought a low mile early t56 for an lt1 got it, clutch, pressure plate, slave and a driveshaft from a 94 trans am for $700 today! from what ive seen that seems to be a pretty fair price. has 80k miles on it. now i need to learn more about them, and making it work with my 86 with a carb-ed 350. i know this is a bit of a different beast than the ls1 t56 the ratios are different, the slave set-up, face plate and input shaft are different. ive heard these have stronger synchros. i see there are three elec. plugs on it, one i assume is speedo(can i switch it to manual speedo?) one is reverse lights one i think is for something called speed shift?

i am looking for some more specs, some ins and outs, some trouble spots to look for, some install mods ill need to do to get it in my 86 swb (2wd obviously) and some verification i paid a reasonable amount for it.

thanks for all your help in advance!

ps i am newer and love this site, what a collection of knowledge! i tell everyone who will listen about it! thanks to the admin- good work!

[ulakovic22]

$700 is a great price. There should be more than just 3 plugs. There is the VSS, Skip Shift, Reverse Lockout and backup lights.

If you have a small hump you will need to cut it out for the trans to clear. You will also need to move the shifter location up to the inspection cover using a Kiesler kit.

86+ had a one piece so you should be able to use the flywheel and the bellhousing bolt pattern will match up to the SBC fine. it's 153 tooth so your starter should work as well. I don't think the driveshaft will be long enough, but I don't know. Mine's still laying on the floor.

If you have headers you might need work them around a little to clear the slave setup on the LT1, I had long tubes and had slight issues.

[superwade57]

how does the skip shift work and what do i need to wire to it make this tranny work for me, do i need to relocate the shifter or is it in an okaay place to just use bucket seats? i dont have the fly wheel from the car it came out of am i able to use any old sbc flywheel?

[ulakovic22]

I don't know about the flywheel, you'll have to do some research on that one. Skip Shift you actually don't want or need, it's a pain, but you do need to either keep the sensor if you have it or buy a plug to plug the hole. You don't have to relocate the shifter, just depends on your preference. Here is a pic of what I had to cut to get my T56 in the truck and mounted up to a stock auto crossmember.

[superwade57]

Thanks for the great info and pics. When you say plug the skip shift is there a plug that I can buy that fits the hole. Does it need constant power or anything. Also Can I swap out the electronic speedo sensor for a manual one?
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[77 350 Shorty Wide]

Good Afternoon, You'll need a flywheel for a one-piece rear main seal block. Not any old sbc will work. Good lick and God Bless, Terry

[superwade57]

thanks for the advice. will a flywheel for a one piece rear main bolt right up to my late 70s block sbc or is there an adapter plate ill need or can get? thanks again

[ulakovic22]

Flywheels bolt to the crank, so it depends on your crank. You mentioned earlier that you had an 86+ and I thought you meant engine, but apparently not. If you are going to bolt up a LT1 T56 to a 2-piece RMS crank/block then you need to get a flywheel that will bolt up to a 2-piece. If you have an old SBC flywheel you might do some research to see if it will work. I'm not sure if there is a thickness issue or if flywheel dimensions are all pretty std.

[superwade57]

thanks a ton guys keep it up. sorry for the confussion it is an 86 truck, however the motor is a gm goodwrench crate motor that i got used from a friend, i seem to remember running the numbers before i put it in the truck and im pretty sure its an older block. i see there is an adpter flywheel so to speak but for 429 bucks! seems steep i am curious is any old sbc wheel will work with this trans, if they make a special one i am inclined to say i cant but dont know for sure. but realistically for almost 500 bucks by the time its shipped i could buy a vortec 5.7 lol and problem solved. but would rather my next motor swap be to a 6.0. but i hopefull you guys will keep viewing and posting here, and ill find a cost effective solution. heres another question, would i be able to keep my bench seat if i got, say a hurst shifter in the style of the old manual trans cars with bench seats from the 60s,70s or not?

[77 350 Shorty Wide]

Good Morning,

No bolting a t56 to an older 2piece rear main block is more complicated than just finding a flywheel that fits the correct older block. Even though the bellhousing that fits a late model Lt1 t56 will bolt directly up to the older style smallblock it's not all you will need. Do some more research.
There is an issue with the hydraulic clutch, pressure plate, disc and the bell housing from an lt1 t56 that do not match up with the older style flywheels, also if you have an ls1 transmission it's another set of things all together. it has to do with distances of travel and such for proper operation. There are companies out there that have the proper parts available for the swap. If I remember correctly you do need a special flywheel like you mentioned. Centerforce I know use to make them and I'm sure others do as well. There was even a company that made a special bell housing to do the swap instead of using the one piece flywheel clutch parts. It allowed you to keep the older style pieces.

I don't remember all the info for this swap it's been almost ten years since I looked into doing it for a '69 Camaro Pro-Touring project that I was thinking of doing.

There is a lot on information on this swap over on "camaros.net", first gen. Camaro owners have been doing this for a long time now into their cars.

As for the shifter there are kits you can buy that can move the location of the shifter. I don't have any idea of what it takes or how expensive but I know they are available. Also I think a bench seat with the old style notch in the upholstery like the old tri 5's use to use would look very retro in your year of truck.

Good luck and God Bless, Terry

[superwade57]

Thanks Terry the center force part number is 700107 for that fly wheel but at 400 + dollars I'd buy a vortec and put it in for another 200 bucks lol
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[ulakovic22]

There is nothing else needed for swapping things over. Since I've built a pretty strong BBC, I used a 64032-4A-07. It's a McLoed street twin since I've got some power, but it's so I can run a 502 block (1-piece RMS) with a 2-piece crank with my LT1 T56 behind it. I had to use an adapter for the crank since it's a 1-piece block, but that's it. I still used all the stock LT1 hydraulics.

For your application, a 85 and down 2-piece crank/block with a 1 1/8 x 26 spline pull style clutch I think part# 460370 would work, but I would need a little more info. Apparently the main issue though is that it's out of your budget right now. Either save up or sell me the T56

[weaintscared]

Lots of info here, with out me asking questions

[dznucks]

I was going to start a new thread, but thought i would bring this one back to the top so all the info stays together.

I just bought an LT-1 T-56 out of a '94 firebird. I have done the research on what it takes as far as a clutch and flywheel. I have some other questions that i have not seen addressed anywhere else.

1. Does the bellhousing crossmemeber (3-speed) need to be removed? It looks like a tight fit and changing the clutch would require complete engine and tranny removal if its left in.

2. Is a high-hump required or will a low hump work?

3. How much did the driveshaft need to be shortened? (just trying to get a rough idea)

4. Has anyone put a hydraulic clutch master cylinder on a '69 firewall? If so, can you show pic's? I have seen the write ups posted on the board, but they arent in a '69.

Thanks
Zach

[dznucks]

ttt

Anyone?

[Captainfab]

I can answer only 2 of your questions. 1) Yes you will need to remove the original bellhousing crossmember. 4) I don't have the pics, but forum member YukonJack installed a hydraulic clutch in his 4x4 and I believe it is a '69 or '70. You might do a search for his build thread, or send him a PM.

[dznucks]

Thanks CaptainFab.

I have seen Yukon's posts. I need a different solution to stiffening the firewall. I like his plate, but i dont have the resources to duplicate that. I was looking for other ideas.

[vortech71chevy]

The low hump clears fine in my 71 swb.

[dznucks]

Thanks for that bit of info Vortech, can you post some pics?

I'd like to get an idea of how much clearance there is with the low hump, how far front/back your motor is mounted, exhaust routing, and your crossmember.

[ColinOpseth]

If you don't hook up the skip shift solenoid you'll be fine. It will shift like normal. The skip shift solenoid is engaged by the PCM. Only at certain engine parameters (i.e. certain throttle position and speed) is the solenoid disengaged. If you don't hook up the solenoid it will never be engaged.

If you don't use a PCM you'll have a problem shifting into reverse because the reverse lockout solenoid locks out reverse by default. You can still "crash" through the gate but you have to put more pressure on the shifter. I don't have a the skip shift and reverse lockout solenoid hooked up on my '72 Vega and it spins into 4th gear.

[ColinOpseth]

Originally Posted by 77 350 Shorty Wide

Good Morning,

No bolting a t56 to an older 2piece rear main block is more complicated than just finding a flywheel that fits the correct older block. Even though the bellhousing that fits a late model Lt1 t56 will bolt directly up to the older style smallblock it's not all you will need. Do some more research.
There is an issue with the hydraulic clutch, pressure plate, disc and the bell housing from an lt1 t56 that do not match up with the older style flywheels, also if you have an ls1 transmission it's another set of things all together. it has to do with distances of travel and such for proper operation. There are companies out there that have the proper parts available for the swap. If I remember correctly you do need a special flywheel like you mentioned. Centerforce I know use to make them and I'm sure others do as well. There was even a company that made a special bell housing to do the swap instead of using the one piece flywheel clutch parts. It allowed you to keep the older style pieces.

I don't remember all the info for this swap it's been almost ten years since I looked into doing it for a '69 Camaro Pro-Touring project that I was thinking of doing.

There is a lot on information on this swap over on "camaros.net", first gen. Camaro owners have been doing this for a long time now into their cars.

As for the shifter there are kits you can buy that can move the location of the shifter. I don't have any idea of what it takes or how expensive but I know they are available. Also I think a bench seat with the old style notch in the upholstery like the old tri 5's use to use would look very retro in your year of truck.

Good luck and God Bless, Terry

Lots of misinformation here.

1) Centerforce makes a conversion flywheel. The part number is 700107.
2) The LT1 bell housing matches a SBC block without problems. The hydraulics are a cinch to setup. The reason you have to use a conversion flywheel or LT1 flywheel versus a conventional flywheel is the LT1 is a pull-style clutch. This means that the hydraulics push on the clutch fork and pull on the fingers on the pressure plate. In other words, it's a Valeo-style clutch and the pressure plates are only made by one company. The heat generated by the Valeo-style clutch meant GM had to run a thicker flywheel.
3) LS1 T56 transmissions bolt up fine. You will not use two of the bolt locations on the SBC but there will still be plenty of bolts installed (5). The LS1 used a longer input shaft and the throwout bearing is hydraulic instead of conventional. Thus, the hydraulics don't interchange. You can swap out the input shaft for an LT1 input shaft and use an LT1 bell housing if you want but it means disassembling the transmission to do that.
4) The Keisler shifter relocation kit is about $400 and it requires you to disassemble the transmission.