Band lever help

PolaraFury · Aug 13, 2021

I’m doing my homework to rebuild my 727 and I was reading a thread about and the author suggested using a 3.8 band lever over the stock one.

I’m not exactly sure what or why a 3.8 lever would be better over stock.

can someone enlighten me?

my plan is to run CRT race rebuild kit, a deep pan, new bands, and (possibly) billet servos.

the trans already has a 2500 stall and a shift kit. I plan on re using both.

69L48Z27 · Aug 13, 2021

The 3.8 is the lever ratio. I forget the range but it’s in the 2-5 range. As a builder, it’s just what the author prefers. I think it would effect the pressure and/or how quick the band applies.

66Satellite47 · Aug 13, 2021

The 3.8 lever is what Mopar used in the HP 727's (other than the Hemi 5.0). It works well with both hard bands and flex bands. It gives a good apply pressure. But the whole combination of front clutch setup and valve body need to work together. Over the years I've used both the 5.0 and 3.8 lever and the different combinations of front servo springs (wedge dual spring or Hemi single long spring). Either 10 or 12 springs in the front clutch with HP style clutch discs for a drag race or HP performance application.
For a while Mopar recommended the 5.0 lever. The 4.2 is rare but seems to work really well. I have 3.2, 3.0(rare), 2.8 (common low perf) & a 2.5.
The higher the number, more the servo travel needs to be, but higher band apply pressure is if the valve body provides it.
Low perf generally use the 2.8. The 3.2 seemed used on the 360 van combo's. The 4.2 was a slant 6.

I'd use the 3.8 for an HP application.
Maybe more info than you wanted.

doctordodge · Aug 13, 2021

Don't forget a billet front drum as well. Your right foot and floor pan may thank you. I experienced one explosion and was fortunate enough to have a scatter shield in the car.

dvw · Aug 13, 2021

No need for an expensive kit, billet servos, or billet drum at your level of performance. Heck we dont run billet servos in anything. My 9.0 car has 750 passes on stock servos. Levers come in 2.7, 3.2, 3.8, 4.2, 5.0 The higher the ratio the greater the holding power of the band in 2nd gear. A 3.8 lever will hold 900hp. How much rate do you need? I've run 2.7 levers in my 11.0 car with no problem. Many cars running in F.A.S.T. use a 2.7. You can use a transpartsonline.com kit. Make sure you have a 4 clutch front drum. 12-15 springs. Shoot for .065" clearance in the front clutch. Rear clutch .025"-.040". Deep pan is a good idea. 518 overdrive pans fit and are less than $50. Make sure you get a filter extension. CRT has a nice one.
Doug

PolaraFury · Aug 13, 2021

I have a B block 500ci stroker and it runs very strong. I haven’t gotten the car set up enough to put it in a dyno but I’m guessing it’s an easy 500 HP (and some change)

It will mostly see street use but once I get it all set up I would like to see what it runs in a 1/4

dvw · Aug 13, 2021

PolaraFury said:
I have a B block 500ci stroker and it runs very strong. I haven’t gotten the car set up enough to put it in a dyno but I’m guessing it’s an easy 500 HP (and some change)

It will mostly see street use but once I get it all set up I would like to see what it runs in a 1/4

My recommendation stands for your combo. Raybestos or Alto high energy green frictions will easily stand up to 700hp.
Doug

66Satellite47 · Aug 13, 2021

A 500 ci 400 will easily make 500 HP depending on the heads & cam. The 3.8 lever with both springs in the servo, 4 disc front drum with red or other race clutches, 12 springs and .065 or so clearance will be good. I ran the stock rear servo, plain rear clutches, deep pan, Cheetah valve body for 20 years in my bracket race 727's.
dvw gives good advice.

PolaraFury · Aug 13, 2021

dvw said:
No need for an expensive kit, billet servos, or billet drum at your level of performance. Heck we dont run billet servos in anything. My 9.0 car has 750 passes on stock servos. Levers come in 2.7, 3.2, 3.8, 4.2, 5.0 The higher the ratio the greater the holding power of the band in 2nd gear. A 3.8 lever will hold 900hp. How much rate do you need? I've run 2.7 levers in my 11.0 car with no problem. Many cars running in F.A.S.T. use a 2.7. You can use a transpartsonline.com kit. Make sure you have a 4 clutch front drum. 12-15 springs. Shoot for .065" clearance in the front clutch. Rear clutch .025"-.040". Deep pan is a good idea. 518 overdrive pans fit and are less than $50. Make sure you get a filter extension. CRT has a nice one.
Doug

Thank you

tonysrt · Aug 13, 2021

Are the lever's marked with the different numbers? Never been inside an Auto so just curious.

oldbee · Aug 13, 2021

PolaraFury · Aug 13, 2021

Question

What is the common stock ratio for the lever?

66Satellite47 · Aug 14, 2021

PolaraFury said:
Question

What is the common stock ratio for the lever?

All depends on what the trans application was from the factory. The common low perf were in the 2's, higher power got the higher number. Read my post #3.
The lower the number the less band apply pressure you get.
IMO only the Hemi got 5.0 lever stock with wide drum & wide band

Dipstick · Aug 14, 2021

The various levers.

PolaraFury · Aug 15, 2021

66Satellite47 said:
All depends on what the trans application was from the factory. The common low perf were in the 2's, higher power got the higher number. Read my post #3.
The lower the number the less band apply pressure you get.
IMO only the Hemi got 5.0 lever stock with wide drum & wide band

Now all of this is starting to come together in my thick skull

thank you

Band lever help

PolaraFury

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dvw

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