I was wondering if anyone on here has put a 6 speed in a 70-72 Skylark.Like a t-56 out of a late model F body. I would like to do this and was wondering what is involved.
do some searching because there are guys on this site who have installed new tremac 5 & 7 spd trannies in their a-bodies.
i hope to be the first and actually claim it. I just need a 455..... From what ive seen most people give up and go with the TKO kits however i think thats too expensive. I plan to take a late model LT1 T56 (you could also use an LS1) and use it behind a 455. A couple of concerns though, the 455 will quickly exceed the transmissions capabilities (at 450 ftlbs), but that would assume youre running slicks. This can be remedied for about $800 if you rebuild the trans to viper spec and the it can handle about 700ft/lbs. Its not too hard, i dont know why more people havent done it...... http://www.v8buick.com/showthread.php?t=180203 http://www.v8buick.com/showthread.php?t=184903 http://www.v8buick.com/showthread.php?t=173239
insome of the research that i have done i have concluded that the t-56 does not bolt up the a non chevy bolt pattern motor, you will need a conversion plate which sets the tranny back which gives you firewall issues. it's also about 1,000 more then a tko. now the good news, you can get a tko-600 (5 speed) which will handle about 600 horse power and 600 ft pounds of torque (the aftermarket t-56 is prety much bulletproof and will handle prety much any street application btw.) these are "realistic" numbers and not the bogus numbers that you see when you read that the 455 put put 510 ft lbs or torque (my very healthy 455 was dyno'd at 400 ft lbs. of torque at the rear wheels) now while it dosent sound as seksy as a 6-speed, you CAN purchase a tko600 with the same final drive gear as the t-56 (which is .64) so you only lose a gear and the rights to brag that you have a 6-speed.
Sorry Dan; Im gonna have to disagree with just about all of that. First off, final drive in a T56 was most commonly 0.5. Some of the earlier ones had the 0.64, they were not optimally designed, and you can "upgrade" to the 1000hp+ gears with reduce the 0.5 6th gear down to about 0.64. For what its worth, thats the difference between 1.5 tanks of gas over a 4 hour trip, or just over 1/2 a tank of gas with 3.42 rear gears and a 26in tall tire going about 65-70mph. Here is a DIRECT quote from Keisler engineering, i can show you the invoice if you like. My freind quoted this for his BOP engine (olds 455) with absolute minimum items so we would not have to fabricate too much. All extras are listed as required, and this does not include that "direct fit shifter stuff". If some of the prices seem outrageous, try searching for SFI approved parts and you will see the kit is quite a bit cheaper. It comes to $4801.60 BEFORE tax, which is almost $7k cdn. Thats pretty damn expensive for a trans...... :af: $3000 kit (minimum) - includes everything but extras: $699.99 for olds bellhousing and flywheel $299.95 Clutch $399.99 for pedals and clutch linkage $131.80 bolts, pressure plate, shifter $275.00 shipping so $4800 USD = 6825 CDN with tax. :Smarty: So lets say you DECIDE you want to put a stock T56 behind a 455. Well the issue comes (as mentioned with bolting it to the block). There are two schools of thought here. You could get some sort of an adapter plate and bolt the bellhousing to the block, or use the Weir hotrod products BOP bellhousing for a T56. OR You could get the SFI bellhousing from lakewood or Mcleod and the conversion plate. This would set the T56 back a little bit, but thats wouldnt cause it to hit the firewall.......??? You definately have to cutout pretty well ALL of your trans tunnel though, and that CANNOT be avoided if you expect to get the correct pinion angle. The cutup trans shouldnt cost much to fix from a competant bodyman. Stock T56 (if you do the search) can be had for $800-$1500 nowadays. There seem to be complete "kits" out there for around $1600-$2000 from a running F-body car. However, since the clutch parts might not be useful, lets not call that a total just yet. Now comes the clutch parts. There are two schools of thought here. 1) You could decide that you wish to use the T56 intended clutch (be it the LS1 type or the LT1 type). The LT1 type is incredibly limited being the PULL style clutch, and thus very expensive and not too many options. However it is one of the smoothest and lightest clutches i have ever operated. The LS1 isnt that scarce of a design, but still expensive. To use this method, you would have to phone up a flywheel manufaturer (or a really good machinist). Centerforce or Mcleod would be the best bet. You would have to send them a sample flexplate (so they could get the bolt pattern) and identify which trans and which clutch you plan to use. They would then fabricate a custom flywheel for your application. Cost $500 <-----which is cheap, because the SBC centerforce "conversion" flywheel that is mass produced has only been lowered to just unnder $400 after many years now...... This would however cause an issue with the pedals and hydraulics. Mcleod sells hydraulics with custom length lines, but this would have to be adapted to A-body pedals, or F-body pedals would have to be adapted to the A-body. (or you could purchase this part from Keisler since the T56 and TKO are almost identical when it comes to function and pedals/clutch parts). 2) You could use muncie clutch parts (probably in SFI upgraded form) and a nice heavy duty clutch which will run about $1600 and be good up to 800hp or so. This can be used in conjunction with the conversion trans plate, and stock muncie pedal assembly. (better option in my opinion) but you sacrifice for a bit of effort required to depress that muncie clutch. :beers2: Ok so assuming you want to put in a STOCK t56 and gamble that your 455 (that youve probably built up, if youre considering a T56 trans-plant, is only 400ft lbs at the wheels [so probably close to 450 at the flywheel]) and hope it will survive (which is should for a long time if you dont use slicks to launch) the total looks something like this. Custom Flywheel Method: $1000 for trans <-----(if you bought a kit for F-body parts for 1K++, sell the parts) $400 for stock clutch/PP system $500 for custom flywheel $20 for pilot bearing $150 for a decent used performance shifter $350 for driveshaft modification $200max for body work to patch floor. $300 for adapted hydraulics system to work the T56 clutch. (Weir hotrod products also sells a solution for this incase you dont want to fabricate anything). + 300 fudge factor for any hardware that you may need to install this. Thats $3250----total. vs. almost 5k. These are CDN prices that I listed, but you can make them USD it wont matter. Muncie Bell/Adapter Plate method. http://www.thegearbox.org/catalog/item/3838217/4803441.htm $800-$1000 for trans <-----(Now you can sell everything you got with the trans except for the gear box itself and the shifter) $400-800 for clutch/PP system depending on how fancy you want to get $200 - for used 4sp flywheel $150 for a decent used performance shifter $200 Adapter plate $350 for driveshaft modification $200max for body work to patch floor. $300 for 4sp pedals if you dont already have some. $300 to get the trans converted to an LS1 input shaft (if you dont already have one) http://www.thegearbox.org/catalog/item/3838217/3697124.htm $50 i think??? for a conversion "extended" pilot bearing. needed regardless of LS1 input shaft. http://www.thegearbox.org/catalog/item/3838217/6239106.htm + 300 fudge factor for any hardware that you may need to install this. This total varies a bit, but it will average a couple 100 less because you arent spending it on a bunch of "conversion" stuff, and the Muncie stuff is robust enough to handle the power it will be put through. Depends how cheap you can get the muncie parts. Total -----> about $3500 again Now lets say you wanted a performance version, that would EXCEED the capabilities of the TKO kit, which is only rated for 600ft lbs. (FYI the viper spec trans, which is VERY easy to acheive is rated for 700). In this case, i would either buy a trans with low kms for as cheap as possible, or a junk trans that you could rebuild from bottom up. Lets say you got a trans for $800 and will make it a 700hp trans. thegearbox.org is one source for parts Someone from a Different forum quoted me this (his name is Mike) Basically the stock T56 is limited by the shift components (blocker rings, synchro keys, fork pads, etc.) so they are factory rated to 450hp for warranty. Once you add the "700hp" parts: - Carbon fiber blocker rings - Billet Steel synchro keys - Bronze shift fork pads - Steel 3/4 shift fork At that point, the weakest link starts becoming the mainshaft (output shaft). The viper-spec replaces the mainshaft and weaker 2nd gear with viper parts. You then have to machine/sleeve the Fbody tailhousing, and run a viper yoke. That pushes the power level up to 800-900 hp. Beyond that, the gears themselves start becoming the weak link, because of the angle that keeps them "quiet". The Transzilla replaces all the gears with custom made straight-cut gears. These are noisy, but raise the rating up over 1100-1200hp. Somewhere in that range also, you'll start stressing the carbon-fiber synchros and missing shifts or breaking them trying to powershift. So they also offer faceplating, that removes the synchros, and gives a direct engagement, similar to the older pro-shifting mod. http://www.libertysgears.com/faceplate.htm Not really good for any street driving though.. Cost for rebuild parts runs about 1K and lets say another $450 for labour for someone to install them. Cost for a Built Up T56. $1000 for trans <-----(Now you can sell everything you got with the trans except for the gear box itself and the shifter) $1600 for clutch/PP and Flywheel rated to 800hp $450 - for SFI bellhousing $50 for pilot bearing $150 for a decent used performance shifter $200 Adapter plate $350 for driveshaft modification $200max for body work to patch floor. $300 for 4sp pedals if you dont already have some. $1000 for parts (including LS1 inputshaft and above mentioned performance shift components). $450 labour to install them. + 300 fudge factor for any hardware that you may need to install this. Total in this case is $6000...... However, if you were going this route, it would make more sense to buy a junked T56 and build it with whatever parts you wish. You can also save the $450 in labour if you do it yourself. However you are good to almost 800hp and dont have to worry about it breaking for a LONG time. Also, if youre going to compare $6000 vs $5000 keisler kit, remember keisler kit doesnt have tax on it yet, they use a cheaper (much cheaper and less capable clutch), THAT trans is not rated for as much power as this one anymore, and its missing a 6th gear. As far as one being more expensive than the other, you will never be able to compare apples to apples. So figure $4000-$7000 for any type of T56/TKO install regardless of how much you "skimp" on the parts to try and save costs. Its just what it costs, and it all costs the same!!!! ou: YOU GOTTA PAY TO PLAY.
OOPS!!! Sorry Dan (again) i just realized there are two adapter plates in question here. You were referring to the Block to Bellhousing adapter plate (which may very well interfere with the firewall, i cant say i have no experience with them). I am referring to the Bellhousing to Trans adapter plate which is not much thicker than a muncie midplate.... This wont cause too many firewall issues. However that trans tunnel needs to come out no matter what. :beers2:
Azeem thanks for sharing the conversion info and pricing, that should be a big help to someone wanting do to such a conversion. One thing to consider a OD trans ratio of .5 with a 3.42 rear gear and a 26" tall tire at 70MPH results in a loafing 1557 RPM. That seems perfect from a fuel mileage and interstate cruise stand point. But depending on the camshaft and how much advanced ignition timing you have a well built 455 may not like to loaf along at that low of a RPM. I know my engine with a 530" lift and 247 duration at .050 and 107 lobe seperation and 32 degrees ignition timng advance will not run under 2000RPM smoothly. I have found if I lower the advance you can lower the minimum RPM threshold.
When I was looking at putting a T56 in my GS what I discovered is that the T56 is too large to put in without modifying the tunnel. You need to either cut the tunnel out and reshape it or if you dont the transmission sits to low and the pinion angle is bad. I did not got any further after that. Mark
Youre right it depends on the engine. Actually i just checked my numbers, it was a 25in tire not 26 (235/60/14). in my 87 firebird and chev 355. I had a double pumper 4 corner idle holley 750 on top. I drove to montreal on a single tank of gas and used just over 1/2 a tank (about 34mpg). On a seperate occasion i used only 5th gear, and it ended up being just under 1.25 tanks or gas at 120km/h. The car has a 3.42 rear gear, so i just lived with it, but the ideal gear is a 4.10. (which would put you at 1600rpm at 62mph)
Theres no getting around this. even with the TKO conversions..... I found the neatest way to do it is cut out the tunnel in one peice from firewall to just behind the trans, raise by two inches and weld in a strip just below. Looks better than hacking it up or putting in a "custom" shaped one. But if you refuse to cut up your tunnel because its a GS or an X, thats another matter.... This is why im sticking to clones
Thanks,for the info people.Azeem that is an awesome amount of good info.I'm only going to run 450-500 hp.At least I can save the $200 on the trans tunnel since I am a bodyman:Brow:
Cant take the credit though, i think it was in Carcraft or something..... And was done to a Chevelle. Also forgot to mention, this involves grinding an "ear" off the top passenger side of the trans. The ear doesnt seem to serve any purpose except hitting the trans tunnel.
I have been thinking along the same lines for my 64. I have to get a ready to go 425 before I worry a lot about that though. Many dollars to go before I have to decide on transmission options, and I have only done a very small amount of research since who knows what left turn may come in my way by then. Would be very very cool in the 64 with a dual quad 425 though!! Lots more fun than an automatic with a floor shifter.
MY GOD!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I dream about hooking the T56 Magnum on to my 455 every night!!!!! Its not really normal or healthy for a 27 years old...???... Anyway, its just a $$$$.$$ question!! Like you guys said, you absolutly hace to cut through the tunnel floor. I have check KEISLER for complete kits and got prices (canadian) and for a T56 Magnum its about , like you said Azeem, 7000.00$ and for the TKO600, 6000.00$, I almost went for the 5 speed, but cant get the 6 out of my head! I got a new question here guys, is it better to use a scatter shield (steel bellhousing) insted of the regular original aluminium with these trannies?? I know it depends more on hte clutch you use, but are they explosive prone...??? And as for gearing, I was originally going for the .50 6th, but after going over it again and again I think th .63 6th gear would be more optimal with my 3.42 gearing. Can wait to do it, hope this year! If you guys ever do the swap, start a thread on here about it, it will certainly contain valuable infos!!!
Marcflag, a 0.50 overdrive would definitely be a mistake with a 3.42 diff unless you are running a very mild cam and possibly EFI... according to the Speed Analyzer on Keisler's website, with a 3.42 gear and a 26" tire (235/60-15), you would be running 91 MPH at only 2000 rpm in sixth gear. The 0.63 final drive in 6th would be the way to go if you have to have a 6-speed. The TKO would require less tunnel surgery and save some money, with about the same result in top gear, but I understand the allure of having six gears. The T56 typically (not always, but typically) shifts a little smoother than the TKO. The T56 Magnum is also already rated for 700 lb.-ft, but a TKO-600 apparently is rated pretty conservatively. I know guys that beat the heck out of their TKO600 with way more power than they are rated for. The TKO is just a much easier conversion, because it will bolt up to a BOP 4-speed bell, no custom adapters, flywheels or clutches. You can use mechanical linkage with no problems, and with a modern diaphragm style high-performance clutch, pedal effort isn't an issue. Just my two cents worth...
haha, here we go again with the 0.50 argument. I had it in my car for a couple years. Its no problem. 0.5 6th, and 3.42 gear. If you dont have an insane cam, and the right carb its doable. My engine was a mild 355 SBC, and i used 6th all the time. 62mph (100km/h) @ 1400rpm and 34 MPG. I did a 4 hour trip on 40L of gasoline, thats pretty damn good.
sorry.. :Brow: ... I just have to bring it up, if I ever spend all that money on a freakin trans, I have to be sure about what I want ahah, hey azeem, did you use the 6th gear north of 1500rpm, im checking the speed analyser, and at 2200rpm your doing 100mph!!!!! Its like with the .50 combination, you cant use the 6th above 1800 rpm or its ticket city....
Unfortunately i did once. I was enjoying the sound of my engine rowing thru gears and i got carried away. Was in the middle of the night on a stretch of highway, with no cars. I also didnt notice what was happening because i hadnt yet calibrated my speedo to read correctly. I let off once the front end felt like it was lifting off the ground. If a deer jumped out i would have been toast!!! Thats all i care to say. DEFINATELY stupid on my part. Remember, if you dont like the 3.42 in there, you have the option to just not use 6th till you can afford to get a 4.10 in there.
