Tranny Conversion
Thread Starter
Pro
Joined: Jul 2009
Posts: 503
Likes: 0
From: Gambrills Maryland
Tranny Conversion
I have a 1968 with small block. Looking for experience on converting 4 speed stock to 5 speed or 6 speed. I have found several conversion kits online that are "bolt ons". Anyone have experience doing one of these installs?
Last edited by omegac1; Oct 11, 2010 at 09:03 PM. Reason: spelling
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Hurst Driveline conversions is a Forum sponsor and I have heard good things about them. They are also known as Classic Chevy 5-speeds and Classic Motorsports. Click on their link on the left side of the page under transmissions.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I have installed both Keislers kit and Classic Motorsports kit. The yare both very good kits and I have had good dealings with both companies. No you do not need to move or remove the engine in either kit. Best price, call each one and compare.
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I had a Keisler 5 speed in mine and last winter out in a T56. It is a whole lot more work and you have to make the cross member removeable. Also major mods or a new cross member is needed. The hole in the floor is changed and a lot more. The T56 is a great transmission but it does not go in as easy as the TKO 5 speeds.
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Safety Car
Joined: Aug 2001
Posts: 4,883
Likes: 11
From: North Easton Mass
I had a Keisler 5 speed in mine and last winter out in a T56. It is a whole lot more work and you have to make the cross member removeable. Also major mods or a new cross member is needed. The hole in the floor is changed and a lot more. The T56 is a great transmission but it does not go in as easy as the TKO 5 speeds.
I wouldn't want to try putting in a T56 into a car with a fixed crossmember. It's ~6" or so longer than the 4-speed and much heavier. The trans tunnel needs to be cut for the shifter housing and you either have to buy an expensive offset shifter or fab one yourself. My 73 frame was from an auto-trans car so I didn't have to deal with the crossmember issue, and I certainly don't regret installing the T56, but you can get 95% of the benefits of the T56 overdrive trans with a 5-speed. I find 5th gear useful even when driving around town but 6th is strictly for highway use.
Rick B.
Intermediate
Joined: Nov 2008
Posts: 40
Likes: 0
From: Gig Harbor Washington
I have the tko 5speed in two of my vettes they are great transmissions.I bought the second one from Tom at Amp Performance in Arizona,He sold me only the parts I needed to install(modified trans, needle pilot bearing,yolk with caps,adjustable bellhousing dowels,and the proper rear mount)I saved over a grand in costs and made the car so much more fun to drive. If you are planing to do this your self, do your home work on this conversion.Search the forum, these trans are more precise than a sloppy old muncie
Instructor
Joined: Oct 2008
Posts: 154
Likes: 5
From: Colorado Springs
I put a Richmond 5spd in 12 years ago. It was easy but I don't remember any of the details. Six gears would be nice though. As 72LS1Vette pointed out 5 gears works great in town but a 6th is nice on the highway.
Le Mans Master
Joined: Dec 2003
Posts: 5,381
Likes: 416
From: N J
I wouldn't want to try putting in a T56 into a car with a fixed crossmember. It's ~6" or so longer than the 4-speed and much heavier. The trans tunnel needs to be cut for the shifter housing and you either have to buy an expensive offset shifter or fab one yourself. My 73 frame was from an auto-trans car so I didn't have to deal with the crossmember issue, and I certainly don't regret installing the T56, but you can get 95% of the benefits of the T56 overdrive trans with a 5-speed. I find 5th gear useful even when driving around town but 6th is strictly for highway use.Rick B.
At 6 inches longer than stock, wouldnt that interfere with the parking brake cable ? Also I believe as the tunnel gets narrow back there will a mod be needed to the fiberglass to clear the yoke ? Thanks.
Instructor
Joined: Jul 2008
Posts: 133
Likes: 1
From: Denmark
Keisler
How far are you with the T45RS with a 2.80 first gear ratio?
I belive that this is one of the most suitable kits for most of us.
I'm waiting to place an order for this transmission kit.
Lars
How far are you with the T45RS with a 2.80 first gear ratio?
I belive that this is one of the most suitable kits for most of us.
I'm waiting to place an order for this transmission kit.
Lars
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
It does get very tight but mine went in with no fiberglass mods. I also use the stock ebrake system with no mods. I did have to modify the crossmember drasticly though.
Former Vendor
Joined: Aug 2005
Posts: 322
Likes: 0
From: knoxville tn
We have two in the field testing currently this option will be available shortly.
Le Mans Master
Joined: Dec 2003
Posts: 5,381
Likes: 416
From: N J
Just a thought...it may not be as strong as the other units, or bolt right in like a kit, but with a few ez modifcations, my 200 dollar world class t-5 overdrive tranny in my 68 works fine for me. 70 mph @ 1750 rpm's with a 3:70 rear end. Been told by many that if I dont beat the living daylights out of it, that it should hold up just fine.