[bigblazer8484]

I have a 84 blazer with a high performance 350. With gas as it is today and the amount of highway driving I do I would like to install an overdrive manual transmission. OR I could add an advanced adapters of gear vendors overdrive to my SM465 and a Dana 20 transfer case I have already. Any advice or new ideas? Anyone ever did anything like this?

 

[Whifflebat]

could swap in an nv4500, that has a nice overdrive in it. I don't know how'd that do with your transfer case though. You may have to do some other stuff too because the case of the 4500 is bigger/taller.

 

[4x4Freak]

You have a D20 in a blazer?

 

[bigblazer8484]

Well i have them (SM465/D20) bought but not installed... I have a TH350-np203 part time in there now. I have also gone through two 700R4/NP208's. I like the Dana 20 bc its strong, its low rage with the traraflex kit and its short. I thought bout an NV4500 or even a NV5600 6 speed...maybe that would be the best way to go. I don’t know how much the transmission would cost but then you would have to buy the bellhousing adapters if i got the Dodge version and I don’t know that much about which transfer case comes with the NV's (or there lows and where they stand in weight and strength). BTW Im going with 35 with 4.10 in one ton axles. I know the advanced adapters overdrive unit(the one that goes behind the clutch in the transmission) only has a torque rating of 450ft/lbs...a number that i might soon be approaching. That leaves the strong gear vendors which...last time i checked... ran around 3K way to much. Anyone have any ideas or is there a product or rig that i missed? Maybe another idea that will keep me rollin down the high way at a nice RPM?

 

[Rastus]

the SM465 with a 205 is very strong. the SM465 with a 208 has an excellent low range.

Micah went with a Klune box behind his tranny on his K5. you can PM him about his setup.

 

[Whifflebat]

You may have trouble with the 5600, if i remeber right its quite a bit bigger than the 4500. From what I've seen priices for a 4500 range from $500ish that needs a rebuild up to $1500 ish.

The chevy 4500's will have 32 spline output, which should match up to a np241 with a 32spline input gear. I'd say a BW4401 too but I don't think they made any pass drop versions. Don't know much about the dodge one though...

I'm currently researching/collecting parts to swap an nv4500 in place of my 4l60e. So far I have the master/slave cylinder and clutch pedals, everything else is just a matter of winning the lottery

 

[bigblazer8484]

the NV4500 is sounding better and better to me...I dont know if the the np241 will stand up being a chain drivn unit... how about any other stout transfers?

 

[mrhoes]

the only time i have heard about anyone breaking a 241 is sitting it on a rock or bashing it on something, i think it can stand up to quite a lot of horse power, dodge put them behind the cummings and their V-10

 

[Whifflebat]

actually the 241 behind the cummins is the 241HD, its pretty beefy...

 

[bigblazer8484]

Oh really well dose anyone know what low ratio it has?... passenger side drop? Also i called advanced adapters and they make an adapter to a doubler any thoughts?

 

[mrhoes]

the low range is 2.72 it has passanger and driver drop, they were in 89-91 k5s passanger drop and in 88 to i think 98 tahoe and trucks with driver drop. I wish i had one because they have more aftermarket parts for them like a slip yoke eliminator and i think some one makes a 4to1 kit for them, but i dont know how long a 4to1 kit would last behind a built 350

 

[bigblazer8484]

With gas prices the way they are now i may just go all out with a cummins-4500-something-D60 and 14BFF. Thanks for the info.. ill keep yall informed