727 rebuild, manual valve body or no

[jdscofield]

Hey Guys,

I'm currently having my 727 rebuilt.  I had already installed a floor shifter and disabled the column shift.  When i drive it, I shift it manually.  Now that I'm rebuilding it, I'm considering installing a manual valvebody along with a mild shift kit.  Will the transmission shift different with the manual valvebody vrs the automatic.  Curious to your thoughts and experiences

[green69rt]

My manual shift body reversed the order of the 1/2/3 shift   Old pattern was P/R/N/D/2/1   With the manual the pattern was P/R/N/1/2/D.  See the diff?  Also when I did mine a new pump relief spring was included and upped the shift pressure so the shifts were much more firm, easy to break the rear tires loose at anything over 2500 rpm on a 1-2 shift.  I loved it, my wife hated it.

If you are getting that far into the tranny, think about a deep sump oil pan for it.  Helps it to run cooler and holds extra fluid plus most come with a drain plug which the stock pan does not have.

[2Luke2]

We got ours from CST and it doesn't have to be a reverse manual it could just be a manual valve body. We haven't gotten to test it out yet, but like you we shift all the time even though it's an auto. Maybe in another week or so we can give you a more hands on review

[jdscofield]

Thanks Guys,

I think i'm going to go with the manual valve body.  I'll let you know what i Think of it in a few days.

[John_Kunkel]

I'm considering installing a manual valvebody along with a mild shift kit.

You can have one or the other but not both, the manual VB IS the shift kit. Shift kits improve the performance of fully automatic VB's.

Will the transmission shift different with the manual valvebody vrs the automatic.  Curious to your thoughts and experiences

Manual VB's are available in forward pattern (stock gear positions) or reverse pattern; reverse pattern is preferred because you upshift away from Neutral (less chance of a missed shift). Manual VB's need no throttle pressure linkage because the line pressure is pinned wide open, this makes for pretty violent shifts at light throttle....some like that, some don't. I find that it becomes a PITA after awhile on the street.

Manual VB's also come with low band apply or not, LBA is more safe but it becomes a PITA because you need to come to a full stop before downshifting to 1st.

Totally confused yet? My work here is done.

[cudaken]

My 70 Cuda has a Semi Manual valve body by TCI. Had a fully manual and did not care for it. With a semi manual it shifts on it own, but you can pull it into any gear you want at any RPM.  So if you are doing 60 MPH, you can down shift into 1st gear.

About shit my self when the slap stick detente went bad and went to pull down to 2nd gear at 50 MPH and hit first by mistake! 5500 RPM's will sure woke up my happy butt! 

Cuda Ken

[jdscofield]

Ok, I got the prices for the different set ups.  $1270 for a standard rebuild, $1425 for a rebuild with a manual valve body, $1600 for a rebuild with a reverse manual valve body.  I understand the shifts with the manual valve body will be hard, especially at low RPM's, and I will probably get tired of it after a while.  However, can anyone tell me what kind of performance gains i will get (if any)  going with a reverse manual valve body versus an automatic with a shift kit.  Main goal is to get the 74 competitive with the new Challenger/Charger RT's.  The car currently has a modified 400, pushing around 300 HP (until i change the heads and cam, then I'll be looking at 400 HP), 3:73 rear end, and a 2800 stall.

[cudaken]

While John is the Trans guy I will add my  worth.

After I had the manual valve body pulled and installed the semi manual, Cuda did not seem any slower by my butt meter. It is a mild 14's street car and have only ran the quarter a few times. 727 was built nasty with a Hemi clutch can, and had a 5.0 kick down installed.

Are you racing the Charger, or is it a street car? One thing I have learned, race car stuff can be a pain to live with on the street! 

Cuda Ken

[Just 6T9 CHGR]

I have had my Cheetah RMVB for 15+ years in my car with no issues.  Street driven car (even though the box it came in says NOT for street use)

Mine does not have the LBA (which makes it more "dangerous" if you lose traction in first, lift off the gas & reapply that gas while still in first to regain traction)  This will blow out the sprag (I think)
You have to get "used to" the driving with a RMVB.  What you can & cannot do etc.

The one thing that saved my butt from missed shifts (missing 2nd gear) with the stock shifter was the Shift-R-Gate made by Duncan-Motorsports.  
http://www.duncan-motor-sports.com/2.html
I was the ginuea pig for his reverse pattern gate.
Upshifting is slap-stick style 1-2 (no button press) and a positive button press shift 2-3...  Downshifting to first has a neutral positive stop as well.  Downshifting from 3-2 can get a bit tricky though.

He now sells the decal I bought elsewhere on his site also

[John_Kunkel]

However, can anyone tell me what kind of performance gains i will get (if any)  going with a reverse manual valve body versus an automatic with a shift kit. 

Unless you can perceive milliseconds, there is no performance gain. The RMVB is all about having total control.

[BSB67]

However, can anyone tell me what kind of performance gains i will get (if any)  going with a reverse manual valve body versus an automatic with a shift kit.

Unless you can perceive milliseconds, there is no performance gain. The RMVB is all about having total control.

Glad you posted it.  I was going to stay silent on this one as I feel I'm always raining on everyone's parade.  

And, driving the pump to higher pressures will actually eat a little power.  Not sure if you could measure that either.

I leave my column shifter in D when I'm at the track racing, or normal driving.  

[cudaken]

I leave my column shifter in D when I'm at the track racing, or normal driving. 

Same here.

[jdscofield]

Thanks for all the insight guys.  I went with an automatic rebuild with a shift kit.  transmission feels good.  However, the transmission guy told me the previous owner lied to me and there was no stall converter, just a stock torque converter in bad shape.  I told him that doesn't surprise me, LOL.  Now just need to find out why a fresh rebuilt motor that is supposedly tuned perfectly is still backfiring and stalling when coming to a stop.  it just never ends