Advice for upgrading to a 5/6 speed for a '73
01-13-2019, 10:17 PM
#1
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Thread Starter
Advice for upgrading to a 5/6 speed for a '73
I am very seriously considering doing a 5/6 speed conversion for my '73 (It has a factory 4 speed). I know theres a few guys out there that make perfect fit kits for them. I am taking the car on the Corvette Caravan in August and on another road trip earlier in the summer. So it'll be seeing a lot of highway driving. These are the questions I have:
1. Which do you prefer? The 5 speed or the 6 speed? What do you think would be a good choice for my '73? I have a L48 350 and 3.36 rear gear.
2. Is this an install that I could do in my garage? Or should I take it somewhere to be installed? I am fairly handy but I am a novice at best.
3. If I take it somewhere for the install, what's a fair price? Does anyone have any suggestions for an installer in the Tampa Bay, FL area?
4. Who do you all recommend I purchase a kit from?
Thanks in advance!
1. Which do you prefer? The 5 speed or the 6 speed? What do you think would be a good choice for my '73? I have a L48 350 and 3.36 rear gear.
2. Is this an install that I could do in my garage? Or should I take it somewhere to be installed? I am fairly handy but I am a novice at best.
3. If I take it somewhere for the install, what's a fair price? Does anyone have any suggestions for an installer in the Tampa Bay, FL area?
4. Who do you all recommend I purchase a kit from?
Thanks in advance!
01-13-2019, 10:33 PM
#2
Race Director
Last summer I did the Silver Sport 5 speed install, a 6 speed is overkill and the added size is a PIA and may require the floor to get cut. If you want to make the install wasy you lift the engine and move it forward after removing the clutch fan hub and fan. Lots of room and easy to get in. The corvette shifter and driveshaft they give fit perfect.
Shops around her charge from $800 to 1500 to install … Can be done in one long day.
The direct fit kit Silver Sport has makes the install straight forward. Talk to Jack at Silver Sport he can give you the lowdown.
I went with the .6 overdrive and love it. I have a 3:55 rear and cruse at 1800 at 75.
If you don't get a kit - you have to cut the drive shaft and make a mount for the trans .. Just not worth the hassle for me. Then you can't go back to stock. With the Silver Sport kit you can go back to stock easy...
Shops around her charge from $800 to 1500 to install … Can be done in one long day.
The direct fit kit Silver Sport has makes the install straight forward. Talk to Jack at Silver Sport he can give you the lowdown.
I went with the .6 overdrive and love it. I have a 3:55 rear and cruse at 1800 at 75.
If you don't get a kit - you have to cut the drive shaft and make a mount for the trans .. Just not worth the hassle for me. Then you can't go back to stock. With the Silver Sport kit you can go back to stock easy...
Last edited by BLUE1972; 01-13-2019 at 10:39 PM.
01-16-2019, 01:32 AM
#3
Racer
Member Since: Mar 2013
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I did a t56 before there were kits. It was still pretty easy. Have the driveshaft cut n balanced. Used a billet aluminum VW 3/4in
inside diameter clutch/brake master with a braided line to the slave. Made my own shifter plate out of aluminum. Used a sawzall to cut out the center part of the crossmember n bolted in 1/4” plates to shim up the trans in line. You still need a special flywheel to adapt it for the correct center pull clutch asm. It all depends on how much you want to pay for or create by yourself.
inside diameter clutch/brake master with a braided line to the slave. Made my own shifter plate out of aluminum. Used a sawzall to cut out the center part of the crossmember n bolted in 1/4” plates to shim up the trans in line. You still need a special flywheel to adapt it for the correct center pull clutch asm. It all depends on how much you want to pay for or create by yourself.
01-16-2019, 06:52 AM
#4
Race Director
Depends on budget and skills. Under 2k budget, T5 from an 88 Camaro. I got one for peanuts, but am a very talented shopper and reasonably talented mech.
01-16-2019, 03:28 PM
#5
Melting Slicks
I used the silversport kit.. I upgraded the trans to the 600 ft lb torque. My little 434 cu in small block required the upgrade. I have a lift, so it was a pretty straight forward install for me to do. I also opted for the .64 od. I have a 3:55 r&p.
The 6 spd trans is physically much larger as mentioned. If you are planning on doing hpd events the .87 od may be a better option. For autocross, rarely will you see 3rd gear. Very happy with my choice.
The 6 spd trans is physically much larger as mentioned. If you are planning on doing hpd events the .87 od may be a better option. For autocross, rarely will you see 3rd gear. Very happy with my choice.
Last edited by Sunstroked; 01-16-2019 at 03:29 PM.
01-16-2019, 10:28 PM
#6
Advanced
Thread Starter
So my '73 is more of a driver, although it does get some spirited driving every now and then. Lead foot, just can't help it 
Thank you all for your input. I'm starting to think a 5 speed would be the best route for this, probably a TKO 500 kit from silver sport.
That being said, is this something that a novice could do? Or is it something I'd be better leaving to a shop? And if so, does anyone know any good shops in Tampa Bay, FL?
Thank you all for your input. I'm starting to think a 5 speed would be the best route for this, probably a TKO 500 kit from silver sport. That being said, is this something that a novice could do? Or is it something I'd be better leaving to a shop? And if so, does anyone know any good shops in Tampa Bay, FL?
01-17-2019, 05:01 PM
#9
Le Mans Master
I got my Tremec kit from American Power Train. The kit had everything needed to install the transmission. I got the 600 series with a .62 overdrive. I have 4:10's so I am tacking about 2300 rpms at 70 MPH. If you have a 3:36 rear, consider a .82 overdrive. That will give you an equivalent rear end of 2.76. The first gear in the Tremec is lower than the Muncie so your off the line gearing will be better. I installed mine in my garage and it took the better part of a day to get it done. My 66 is on the top bunk of my lift, so if you want to see the finished product, PM me. Lastly, check with the sop doing the install and see if they have done one in the past. The bell housing must be matched to the block with a dial indicator or you could experience some serious vibration. Check the internet for more information. Jerry
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USMC 0802 (01-18-2019)
01-18-2019, 09:17 AM
#13
Team Owner
Kevin at Silver Sport Transmissions is the guy to talk to. Very knowledgeable and extremely helpful. I'm doing the TKO 600 with the .64 overdrive next month.
Last edited by Capt. Shark; 01-19-2019 at 09:54 AM.
01-19-2019, 09:53 PM
#14
Melting Slicks
Its not really a vibration problem. The hole in the bellhousing that positions the transmission must be perfectly centered for the Tremec. Due to the tapered bearing on the input shaft it will not tolerate being off center. The Muncie is more forgiving. When I did mine, the engine was not in the car. I'm pretty sure it would be much more difficult to do it in the car. Not saying it can't be done by any means, but make sure you have a plan to make sure it is within spec before installing the new trans, or you will take out the input shaft bearing on the new trans in a hurry.
01-20-2019, 03:23 AM
#15
Team Owner
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St. Jude Donor '05
Check around your local trans shops. once in awhile youll get lucky and they could have a T5 in nice shape like Derek spoke of. For a stock L48 they are fine, no need for a 6 gear with what you are running.