To my knowledge there is a lack of information out there on the right procedure for this. What needs to be changed, what needs to be modified, what you will need etc. I understand the G56 and NV5600 deal and how the New Venture is stronger due to its cast iron case etc. but I would like to get a combination of everyones knowledge to how this is done. Preferably from the people who have performed it if there is anyone but if you havent performed it but know some things feel free to comment. The reason I am deciding upon a 6-speed vs a 48re is the facts. The 48RE is an amazing transmission when it comes to stock power levels and even with billet internals it will handle quite a bit of torque and power. What it comes down to though is a signifigant difference in prices. Baseline price on a fresh remanned G56 transmission is $2500. From there you want a nice clutch so maybe another $1200 to 1300 bucks (not talking the bulletproof 1000+ hp version) but reliable to atleast 650 hp. Lets talk auto transmission seems cheaper right? especially seeing as I already have it. Well lets start at a triple disc converter just for laughs Goerend has one available with a lifetime warranty for $1300 bucks. Okay now your converter will never slip again... well thats great? Now lets be realistic if you put 200 hp through it. It might hold for some months to come... But you forgot about the rest of the weakpoints. So you want billet internals. Okay lets go full billet before we snap a shaft? Alright were talking roughly 750 a piece for reliable ones.. We'll go Goerend here again (simply because they have a good price and a good name) Take 750 (roughly) times that by 3 for your input, output, and intermediate shafts. Your at roughly 2200 bucks for just the shafts. So thats a total of $3500 in your auto already? Now take mine for a prime example im at 80000 miles roughly and rumor on the street has it the clutches in these things start going out at 100000 miles plus Im adding power = more stress == lessen the life of the transmission. So overhaul kit just to be safe? Some kind of kit with a billet accumulator piston so lets go BD. A BD stage 3 overhaul kit with the billet ap is roughly $700 (I chose this one because we do not need the added input shaft in the Extreme performance stages) Before I forget we need a valve body too and probably before the billet shafts (my apologies). So lets add a reliable valve body from Goerend roughly $700 bucks we are now at roughly $4900 bucks. Now the transmission is in pretty good shape its gonna handle quite a bit of horsepower. Lets throw a shift kit in (not sure if its needed) and we'll be at or around $5000. Let's remember that figure and pickup on the manual transmission again. The G56 I plan to put in some time from now will have been remanned meaning any worn or damaged parts will be replaced (pretty much new on the inside). So lets figure in the $2500 transmission cost. Id be an idiot to say thats the final price obviously the core on these things is roughly $1000 and obviously there not going to accept a 48RE core for a G56 transmission so Im kind of kissing it on a $1000 bucks there good news is I have an auto I can hopefully sell for some money back anyways. Were at $3500 for the transmission and 1300 for the clutch which puts us at roughly $4800 figuratively speaking. But thats essentially with a transmission at 0 miles people dont usually have issues with these things until they start getting into the higher miles area round 90,000. So that gives me 6 years of average driveability and minimal stupidity. Now this is where things start to get foggy for me I know the driveshafts have to be toyed with. I think the front has to be longer so I got a price on a remanned one for 280 bucks and the rear is to be shortened? maybe its the other way around not sure. A clutch hydraulics kit including the slave and master as one assembly is about 150 bucks which aint horrible. Back to what I was trying to say before in that long paragraph is your getting a more dependable transmission for your buck with a standard and that has Fact to back it up. Its in anyones opinion to think what they want but someone elses thoughts could get me stuck with a big investment and a pile of junk underneathe my car. The 48RE is made for stock driving. It can be made to handle power but its still an automatic and automatics just work harder because they shift themselves so they need added parts to make that happen and added parts means added stress and added $$$ thats fact. Im 19 years old I'm gonna want to make power and Im sure Ill have some kind of towing in my future. I dont want to have to worry about this thing failing in my future. And thats what I want to invest in right now not a quick patch on a never healing wound. So therefore I have decided to invest in something thats not perfect by any means but has proven itself in high torque and hp as well as towing applications over the 48RE. With all of that being said does anyone have any input on how this gets done does anyone have any pictures as well? My main questions are as follows:

1. What needs to be done to the drive shafts?
2. Can I keep my auto-shift transfer case?
3. What kind of electrical modifications am I looking at?
4. I understand there is a stamped plate that you can use for a cutting reference underneathe the carpet. Is this true? Also which is the best method to go about cutting this out and making it look somewhat professional?
5. Any kind of modifications to the cross-member?
6. Are there shift lights built into the dash already? If so would the Smarty Flash make them work?
7. Are there provisions for the third pedal?
8. My final question is.. are there any other modifications that need to be done to pre-existing parts such as the t-case? An example of what I'm saying would be the need of a starter spacer when an NV5600 application is used.

Thank you for your time and I hope I can get some good input out of this!

 

I touched on this idea years ago. gave up... two auto trucks l flipped my way into a 6spd truck without the labor .

I think the computer won't like it so count on a manual comp.... not sure about the pedal install... I hate working under the dash.... swapping or cutting the brake pedal down.

your auto shift case is fine. nothing changes.

people talked me out of it every time I got the urge. I won't do the same and I'm sure it's been done.... but is it worth the effort versus just selling that and buying a 6 spd.?

 

Depends on what you want to do. Personally I would go with a built auto versus a manual and having to track down ecms, pcms, cross members, pedals, drivelines, and I think you lose your auto shift t-case but I am not sure.

 

Yeah the good thing is I dont plan on doing this next week or anything like that. I want to have whatever I do planned out whether its build an auto if going manual seems overwhelming but either way I dont want to just buy pieces of whatever I do I wanna get it all at the same time so Im not stuck with a truck that doesn't move.

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The other thing is everytime I see a Cummins with a 6-speed theres an automatic price jump. Like 2-$3000 price jump for the quad cab non-dually's atleast.

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The plan is going to be buy a salvage truck with a 6-speed and all the guts in it.

 

I know this post is old I'm looking to talk someone about this conversation