Transmissions

427sharpe · #1 (**permalink**) 10-12-2001, 08:26 PM

I was wondering if any members have installed a T56 behind a big block? I am interested in the overdrive capability without wanting to go too wide on the other ratios. I shredded a TKO drag racing and am currently back with a close ratio top loader.

Cal Metal · #2 (**permalink**) 10-12-2001, 09:22 PM

You might want to visit David Kee's site www.4speedtoploaders.com. He has just furnished info on the rare and reclusive "white stripe" toploaders that has a variety of road race ratios including the "Sebring Box" HEH CL identification. Pretty neat gear boxes and Dave has done a great job in compiling and presenting the data.

Anthony · #3 (**permalink**) 10-13-2001, 07:49 AM

The T56 is a wide ratio 4 spd with a double overdrive. The first 4 gears are similar to a wide ratio toploader, with the 5th and 6th being roughly .75 and .5 depending upon which T56 application. I checked into this 2 or so years ago, and at that time no one made any adapter, so it would have to be custom made. I spoke with D&D Transmissions, and they knew alot about what it would take, I think another 2-3K$. Get a Super Ford mag, and look in there for their advertisement to contact them.

If you want an "overdrive" capability, then you can use a wide ratio toploader with a 3.07 or 3.23 rear, or if you want a ratio spread similar to a close ratio toploader, then get a Richmond 5 spd with a 2.88 or so rear, or get a 5 spd Jerico or G-Force and get custom ratio's to your liking.

Cal Metal · #4 (**permalink**) 10-13-2001, 08:26 AM

David Kee is currently a Jerrico Distributor. You might want to check with him. Is there any conceivable reason you would want an OD that is .5????

Richard Law · #5 (**permalink**) 10-13-2001, 04:28 PM

I run a 460- 450hp, 520ft/lbs @3000rpm with a T56 and a 3.31 rear. 6th gear (.5 OD) is pretty high (60mph = 1500rpm) but I guess I did it because no one else had one in New Zealand (1994). I bought the trans direct from BW on a trip to the states and they kindly made an adapter plate to fit the Lakewood 460 bellhousing. As it was (at that stage) a corvette box I machined the 460 crank end out to take the GM spigot bearing and used a tilton throwout bearing. The shifter is a Mustang with dummy lockout, reversed as per the original 427. Changes are excellent and the tall shifter provides a great hand/arm rest! Funnily enough you don't notice the 6 gears and I spend most of the time in 5th, however 6th gear running has produced 18/20 mpg which is good in the land where gas is $4.50 per gallon! Have had no problems at all with the box. I have some photos somewhere of the shifter position etc if any one wants.

Dave Samson · #6 (**permalink**) 10-13-2001, 05:30 PM

Richard,
A little off the point, but I just drove 2,400 km to our Nationals and back from the Gold Coast running a supercharged Commodore engine, albeit all on vacuum on the highway, 0.68 5th on a Tremec TKO, 3.45 diff. and averaged 21 m.p.g. fully laden with 2 people. Around town I get 14 mpg. That ratio of 50% better fuel consumption on the highway is pretty consistant for my other 3 vehicles.

427sharpe · #7 (**permalink**) 10-13-2001, 07:48 PM

Richard--
THANKS! That was what I was looking for! I run a 535 cid BBF w/ 3.56 gears with a locked differential. I was looking to go to a shorter gear for drag racing--like a 4.11 or so, but didn't want to give up highway pleasure. I think the T56 will take the abuse (it handles the Viper pretty well) and the .5 6th gear would give outstanding cruise mileage (2.06 gears!) not to mention scary top end. I am sure that ultimate top speed would come in 4th or 5th considering aerodynamics, but it's worth a try. I have a contact to BW in process now. Nice to know they already know how to spool up an adapter for me. Which box did you decide on--I know they make a few different configurations. Again, thanks to all!

RICK LAKE · #8 (**permalink**) 10-13-2001, 10:27 PM

427 sharpe HI RICK LAKE HERE I HAVE A RICHMOND 6 SPD. IN MY COBRA THE BIGGEST PROBLEM IS THE HORSEPOWER AND TORQUE RATING ON YOUR MOTOR. RICHMOND TRANS GOES FOR ABOUT 2800.$ IN JEGS OR SUMMIT CATOLOGS. MY CAR IS A 452 F.I. SUPERCHARGED COBRA . AS LONG AS YOU DONOT USE SLICKS ON YOUR CAR THIS TRANS IS GREAT. IT WILL NOT SHIFT UNDER FULL THROTTLE SOMETIMES FROM 2 TO 3 GEARS AND 3 TO 4 GEARS ON A POWER SHIFT I HAVE 3.31 LOCKER IN A JAG REAR AND THE CAR CRUISES GREAT. IT GETS ABOUT 21 MPG. I HAVE A SMALL BLOWER CAM IN THE ALL ALUM. SHELBY MOTOR. 501 533 LIFT, ENGINE HAS A SMOOTH IDLE AT 800 RPMS CAM IS RETARDED 4DEGREES TO MAKE MORE TORQUE THAN HP. 340 HP 425 TORQUE WITH A FLAT POWER BAND THIS IS MOTOR ONLY

YOU SHOULD TALK TO G FORCE ABOUT THIER GF-5R TRANS.OR E MAIL THEM AT gforce@nbn.net AND HAVE THEM SEND YOU A CATALOG. THIS TRANS IS NOT CHEAP, BUT IT IS VERY STRONG. GOOD LUCK WITH YOUR CAR RICK LAKE

HORSEPOWER IS YOUR FRIEND BUT TORQUE IS WHAT MAKES YOU MOVE

aeroace · #9 (**permalink**) 10-14-2001, 12:21 PM

Try looking into the Liberty 6 speed. Jericho makes the only manual trannys that will live behind a big block and in front of slicks. They can put any gear ratios you want in them. They have straight cut teeth so you can speed shift. If they are too pricey for you, just keep buying $1100. Tremec's from Mexico and take it easy at the dragstrip.