Silver Sport Overdrives.....5 speed manual.... Who has switched a 727 to a 5 spe

[twenty mike mike]

My Passon "Hemi" 4-spd overdrive is excellent, and it's available more or less immediately. It does use different shift rods, but that's no big deal, since they're included. The shifter alignment process is the same as the regular 4-spd. It's about $2000 cheaper than the 5-spd.

If you really want a 5 speed (which I wanted, too, but I didn't want to get in line), it seems that Passon's backlog issue is mainly with the E body versions, and the B body wait is down to six months. That might work for you, since you said you're saving up. Look at it as a good project for next fall/winter, except it'll take a weekend, instead of a month...or more.

There's a lot to be said for an installation that doesn't need any custom fabrication, as you learned from your GV experience. I don't think you can go wrong with either the 4-spd or 5-spd Passon.

[303 Mopar]

My Passon "Hemi" 4-spd overdrive is excellent, and it's available more or less immediately. It does use different shift rods, but that's no big deal, since they're included. The shifter alignment process is the same as the regular 4-spd. It's about $2000 cheaper than the 5-spd.

If you really want a 5 speed (which I wanted, too, but I didn't want to get in line), it seems that Passon's backlog issue is mainly with the E body versions, and the B body wait is down to six months. That might work for you, since you said you're saving up. Look at it as a good project for next fall/winter, except it'll take a weekend, instead of a month...or more.

There's a lot to be said for an installation that doesn't need any custom fabrication, as you learned from your GV experience. I don't think you can go wrong with either the 4-spd or 5-spd Passon.

  I have the Passon 4 spd OD in my Cuda and love it! 

[Kern Dog]

I was planning on keeping my 3.55 diff for this swap but I got to thinking....
The Tremec 6 speed in the new Challengers is paired with a 3.90 axle gear. The 5 speed Tremec has similar 1st through 5th gear ratios. I might go with the 3.91 diff to maintain similar gearing.

[XH29N0G]

I think the 3.91 will be a nice gear with the TKO ratios.

[Kern Dog]

I think so too. The .64 OD reduces the 3.55 to a 2.27 which may be too tall of a ratio to do much other than high speed driving. The 3.91 final drive would be a 2.50.

[Derwud]

I left the 3:23 in my car for now.. 45 mph was best in 2nd gear.. 3:73 or 3:91 are on the shopping list.

[Kern Dog]

The 1st gear final drive ratio with the 3.91 is right in the sweet spot. It makes for strong acceleration without making the driver shift too soon. 1st in transmission (2.87) and a 3.91 diff equals 11.22 to 1. For a comparison, a 727 would result in a 9.57. To get a car with a 727 to launch as hard, you'd need a 4.56 diff gear.

[cdr]

The 1st gear final drive ratio with the 3.91 is right in the sweet spot. It makes for strong acceleration without making the driver shift too soon. 1st in transmission (2.87) and a 3.91 diff equals 11.22 to 1. For a comparison, a 727 would result in a 9.57. To get a car with a 727 to launch as hard, you'd need a 4.56 diff gear.

BUT,, your Charger has a large cid stroker that makes a lot of torque 

[komninon]

my car 68 charger
520 ci   630 torque
tko 600
354 gears  is perfect for me

[Kern Dog]

The 1st gear final drive ratio with the 3.91 is right in the sweet spot. It makes for strong acceleration without making the driver shift too soon. 1st in transmission (2.87) and a 3.91 diff equals 11.22 to 1. For a comparison, a 727 would result in a 9.57. To get a car with a 727 to launch as hard, you'd need a 4.56 diff gear.

BUT,, your Charger has a large cid stroker that makes a lot of torque 

That is true. The 5.7 and 6.4L Hemi engines do not make as much power down low. I have 3.55s in the car right now. I will probably try it with the existing gears and try the 3.91s later to get a feel.

[XH29N0G]

My only thought would be the final drive and cruise RPM with the cam that you have.  If the engine won't lug, stick with what you have.  If it does, then consider the 3.91. 

If you are not choosing based on Highway cruise conditions, then choose for whatever makes the most sense for your application. 

[pipeliner]

I run a close ratio T-56 Magnum in my Charger with 3.91 gears. You will not like that 1st gear at 2.87 with 3.91 gears, it will be useless. In a close ratio 6-speed that first gear is a 2.66 and you can actually use it. Then as follows 1.78, 1.31, 1.1, .80 and .63.  On a regular T-56 you have to go with like a 4.56 gear or lower to use the .50 6th gear. My buddy found that out the hard way, and 1st gear is like a 2.91. An absolutely horrible gear ratio spread on a regular T-56. BTW I did buy my complete kit off of SST.

[ACUDANUT]

"I've wanted to put an overdrive in my Charger for years. I actually had a Gear Vendors for a couple of years but had some troubles with it. I pulled it and sold it awhile ago. Since then I've thought about what options exist. My car has always been an automatic so I leaned toward that. The 518 has worked for some but I thought that if I went with a 4 speed auto, I'd rather use the 4L60E for 2 reasons....The deeper first gear and no cutting of the floor or torsion bar crossmember. The cost though! $5500-6000 ? "

Where did you come up with 5,500-6K for this transmission. ? 

[Kern Dog]

Silver Sport offers a 4 speed automatic kit based on the GM 4L60E, a transmission that dates back to the early 80s as a 700R4. They have 3 levels of durability. I quoted the highest one.

Regarding the 5 speed with a 3.91 diff:
My thought was that it closely matches the setup used in the new Challengers. The difference is that my Charger actually weighs less and my engine makes more torque than the 5.7 or 6.4 Hemi. With a lighter and more powerful car, I probably could use less axle gear and still get good performance.

[ACUDANUT]

Those 700R4/TH700/4L60 cost around 1500 average on the internet.  I need one for my cousin's 86 K5 Blazer.

[Kern Dog]

Well, yeah....for a 200 HP Blazer, a stock based one will be fine.
The new ones are NEW. All the internals are upgraded for durability.
They have a Mopar specific bellhousing. They come with the conversion driveshaft, trans crossmember and mount, speedo cable, ATF lines, all the electronics to run this "electronic" trans, plus a hybrid shifter for the cars with a floor shift and console.

[frank1966]

I run a close ratio T-56 Magnum in my Charger with 3.91 gears. You will not like that 1st gear at 2.87 with 3.91 gears, it will be useless. In a close ratio 6-speed that first gear is a 2.66 and you can actually use it. Then as follows 1.78, 1.31, 1.1, .80 and .63.  On a regular T-56 you have to go with like a 4.56 gear or lower to use the .50 6th gear. My buddy found that out the hard way, and 1st gear is like a 2.91. An absolutely horrible gear ratio spread on a regular T-56. BTW I did buy my complete kit off of SST.

Is the T 56 the only 6 speed option? So a 3.23 rear will not work either in order to use the 6th gear? If this is true then we cant use a 6 speed. The only reason I would consider a 6 sp is I heard it has a much better shift and shorter throw

[frank1966]

I know very little about transmissions, I see that the 727 runs hot, do manual transmissions have the same problem, do you need cooling lines?

[Mike DC]

    

I know very little about transmissions, I see that the 727 runs hot, do manual transmissions have the same problem, do you need cooling lines?

Running hot and needing fluid coolers is an automatic thing.  It's normal for automatics.  Even the ones that aren't known for 'running hot' can usually still benefit from more cooling.  Factory automatics didn't really stop running hot until they got lockup converters.    

Manuals don't suffer from major heat issues.  Not at street legal speeds anyway.  

                   

Is the T 56 the only 6 speed option? So a 3.23 rear will not work either in order to use the 6th gear? If this is true then we cant use a 6 speed. The only reason I would consider a 6 sp is I heard it has a much better shift and shorter throw

5-spds and 6-spds are just an old 4-spd with more gears piled onto the top end.  The bottom 4 gears are still similar ratios on all of them.  The bottom gear ratio is usually in the ballpark of 2.5-3.0 (but the Tremec T500 is a bit lower).  

The 4th gear is a straight-through 1:1 ratio on virtually everything both stock and aftermarket.  On older trannys with less than 4 gears, the top gear (whatever it was) would virtually always be 1:1.  (This goes for automatics too.  The 727 T-flites were 3pds with ratios of 2.45, 1.45, 1:1.)

The choice between 5 or 6 speeds is basically a choice between one overdrive gear or two.  The T-56 6spds have two different sets of OD ratios, a .74+.50 set or .80+.63 set.


This calculator is good for this stuff.  You can click between the various Tremec aftermarket trannys:

http://tremec.com/calculadora.php

[frank1966]

   

I know very little about transmissions, I see that the 727 runs hot, do manual transmissions have the same problem, do you need cooling lines?

Running hot and needing fluid coolers is an automatic thing.  It's normal for automatics.  Even the ones that aren't known for 'running hot' can usually still benefit from more cooling.  Factory automatics didn't really stop running hot until they got lockup converters.    

Manuals don't suffer from major heat issues.  Not at street legal speeds anyway.  

                   

Is the T 56 the only 6 speed option? So a 3.23 rear will not work either in order to use the 6th gear? If this is true then we cant use a 6 speed. The only reason I would consider a 6 sp is I heard it has a much better shift and shorter throw

5-spds and 6-spds are just an old 4-spd with more gears piled onto the top end.  The bottom 4 gears are still similar ratios on all of them.  The bottom gear ratio is usually in the ballpark of 2.5-3.0 (but the Tremec T500 is a bit lower).  

The 4th gear is a straight-through 1:1 ratio on virtually everything both stock and aftermarket.  On older trannys with less than 4 gears, the top gear (whatever it was) would virtually always be 1:1.  (This goes for automatics too.  The 727 T-flites were 3pds with ratios of 2.45, 1.45, 1:1.)

The choice between 5 or 6 speeds is basically a choice between one overdrive gear or two.  The T-56 6spds have two different sets of OD ratios, a .74+.50 set or .80+.63 set.


This calculator is good for this stuff.  You can click between the various Tremec aftermarket trannys:

http://tremec.com/calculadora.php

Thanks for that, this is my first muscle car with an auto tranny, always had stick, mostly never had any tranny issues. Iam most likely not going to stay with an auto - I don't like all of the required adjustments, heating issues, slipping, etc.. I don't know how my car rides yet, it has been of the road since I purchased it. I know now that my tranny link to carb is all wrong, bought the correct parts but not sure how it is suppose to go.

[XH29N0G]

Whether the gear will work on not depends a lot on your engine.  I think my original engine would have worked fine with a 3.23 and a 6 speed.  The way it is set up now would not, mostly because the cam would make the engine really lug along at most speeds I might cruise.

[Kern Dog]

See, that is what some guys need to understand. LOW cruising rpms are great if the engine can run right at low rpms. A 3.23 running through a .50 overdrive will suck ass if the engine has a big cam in it.