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2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
do a search on the t56 for domestics. The research I have found so far says you need an LS1 based t56 for the input shaft length and splines to be the easist to swap. You will need to cut a hole in the top of the transmission tunnel no matter which one you use. If you use a LT1 based unit you have to switch the input shaft because the LT1 is too short (too long) I dont remeber which right now but you have to buy an extension bushing for the crank regardless. If you want to use your stock bell housing you need to make or buy the $200 adapter, summit has them in stock. Go to the gearbox website and you can get info/ alot of the parts there. You need the reverse lock out solenoid and to buy a reverse lockout wiring kit as well. Check SSt for that or summit and the gearbox
I've read to stay away from the viper, austins and corvette t56s. The viper , austins will need a different tail housing and possibly a center adapter plus the LS1 input shaft. The corvette ones need everything changed so theyre cost prohibitive. I would like t56 but with all my research , the $4000 tko 500/600 are the most reasonable unless i find a t56 under $1000
I can post links to some posts for more info later if you need
good luck
Last edited by Rescue Rogers; 11-01-2018 at 06:39 PM.
Oh , I assumed you just wanted any wiring /harness info.
a friend here has a t56 from a Commodore ( Vauxhall?) In his 74 , had to change the rear housing, cut a bigger hole in his trans. Tunnel.
Got an adapter to go to his sbc. Hyd. clutch setup as well.dont recall any reverse lockout setup.his is an old standard t56 .
I can get more details if it helps.
are you looking at a DBS model ? They seem to be the ones with a plain manual 6 speed. If you have found a wrecked one , then getting the unit out on the ground and measure it up would be the safest way to tell if its going to match .if the engines good in the wreck just leave the box on and drop it in the vette as one ! Easy !
Some really excellent feedback here. I asked the fellow to send me more pics of the T56. Let's see what he answers.
Reading a first of many times through, it seems that a T56 from an Aston Martin Vanquish is feasible, but not as straight forward as I thought.
Swapping input shafts and tail housings doesn't bother me as much as the fact that the AM Vanquish were originally paddle shift cars.
I have done input shafts and tail housings (I still need to calculate if it makes economic sense) ...but I have never done a paddle to manual conversion.
Do we have any more data on what it takes to operate that ?
OEM paddle shift ! Awesome idea but in reality it would be wired to the original engine control and possibly bcm. Trying to transplant just that to a carby controlled sbc would be a nightmare.
If it were me I would go look at the "donor" and see what your up against.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
There are sequential shifters on the market ,BUT you need to look at the prices before getting excited.
https://www.s1sequential.com/product-category/sequential-shifter-variants/
A plan is taking shape in my mind. If I can get it for 4-500... I will go forward with it. Ar works I need to rebuild it and swap tail housing and input shaft.
If if he doesn’t answer my question in can sandbag a little
Yes. For 4-500 that does seem like a reasonable conversion project
The only question mark is the actuator. If i simply swap a shifter and tail housing will the work or will rail need to be modified in some way to accommodate human.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
little drinky drinky before typey typey, or does your spell check hate you? LOL
from what I gather if you get the tranny for $500, the adapter plate for $200, the tail housing for$350, $130 for the input shaft, $700 for the premium rebuild kit,( if it fits the Aston box), pilot bushing is $10, , you can keep the stock clutch linkage setup with the adapter plate, the reverse lockout solenoid for $70, and the wiring from american powertrain for about $180 (summit prices) then you're into it about $2250 for a rebuilt 6 speed. Thats pretty good, you'll still need a shifter, drive shaft and whatever clutch set up you choose. so that could be another $500 to a grand but that will happen with a 5 speed as well. You'll need to mod the transmission tunnel, the trans mount and cut and weld the trans cross member to make the center removable.
Let us know how it goes. If the transmission doesnt need rebuilding and you can replace the bare minimum to swap out the input shaft (synchros and bearings) you can save a few bucks but it may not be worth it.
I would call Gearbox and ask them about the shifter questions as well as rebuild kits and bearings for the Aston box, they seem to know what they are talking about
Last edited by Rescue Rogers; 11-01-2018 at 07:12 PM.
If you go forward with this , don't forget the kings ransom the American postage will want to charge you to freight the housing across the pond. Avoid UPS at all costs.
It’s economically feasible IF I can get this for a moderate amount of $$$.
It also seems technically feasible. The last few evenings I have been pondering, weak and weary, over many quaint and curious volume of forgotten T56 lore (chirp - nevermore) and, from what I can gather, it’s not like you have a valve body and governor like an auto trans to worry about. The shift pattern we are concerned about seems to be in the tail housing.
My current engine and M21 are out for the moment. I have to decide if it makes sense to purchase a new clutch kit, rebuild the shifter, etc. Or save the nickels and dimes I would otherwise be spending there for this projects and accepting I probably will not be back on the road by the spring.
The shifter, for a C3 Corvette conversion, should be rearward on the tail housing, correct ?
Well, this project fizzled out. The fellow wants $1000 for an Aston Martin trans. I may have been able to haggle him down, however (other than the dude being particularly unresponsive) there was just too much to modify:
- tailhousing
- input shaft
- main shaft
- cross member
- shifter rail
and those are just the biggies
Doing the math, it just was not economically feasible.
I have found over here a Borg Warner T5. I’ll start a new thread on that one.
10-31-2018, 03:25 PM
T56 conversion compatibility
