Man overdrive w-6.2

[1-tonmudder]

I know that Chevy used a man 4 speed overdrive is some of there trucks,but were they ever behind a 6.2 diesel.

I am needing something to do my commuting/light(er) hauling in and not run my 4dr PSD F-350 everyday.I have three lo-milage 6.2's and am goin to use one of them with the OD or a 465.

My tenative plan is to run the OD with a 3:42 rear or a SM465 with a 3:08 rear.I know it's not goin to be a speed demon,I am just wanting to get at least 20MPG and still be able to haul a few thing's.I have almost all the parts laying around to put together a pretty nice truck and that is why I wanting to try to use these parts.

Has anybody saw this set-up??.Is 20mpg realistic in a 2wd 1/2 ton pickup with either of the trans/gear combo's I listed??

 

[Tominator II]

When I first put a 465 in my 73 K10 that had a Goodwrench 350 motor and a Turbo 350 AutoTrans before that and 3.07 gear ratio and also ran 32" tall 235/85/16s on old early 60s Chevy 16x6" steel wheels it got 18mpg a few times, and I live at high altitude where you can't go anywhere without climbing a pass or 2. Of course I had to put 3/4 ton axles with 4.10s in and mess that up. Then a 454 and mileage really went out the window. I re jetted the Qjet it had with small primary jets (69) and the fattest secondary metering rods I could find. The secondary rods were the kind that are about 1/8 inch thick at their skinniest point. It had decent power too. I have never run a 6.2 Diesel but the ratios you are talking about ought to work pretty good, especially if you run taller skinnier tires.

 

[AJMBLAZER]

I know some of the guys with the CUCV Blazers have talked about getting 20+ mpg with them despite having TH400's and 3.08 gears. I'd think a manual could do even better.

 

[1-tonmudder]

I will probably be running a 235/75/15.That is another reason for me wanting to do this.A load range E 235/85/16 cost's 2-3 times more,and I'm wearing them out riding around.

 

[blakerj1]

I plan on running 255/85-16 BFGs on mine. They are taller, but I am trying to keep from changing the 3.73s behind my 4bt.

 

[1-tonmudder]

A 4BT is what I would like to have but I dont have one of them laying around.As popular as they are now I wouldnt use it anyway I'd sell it.

 

[Chevy305]

that sounds like a good idea...

 

[Lonnie P]

I bought an '82 6.2 w/ 4sp OD trans & 3.08's. The engine was blown, so I have no idea about diesel mileage, but I got 18mpg w/a 350 engine.

I do know those transmissions are junk. I had so many of them go bad, that I finally swapped to a th400 & lost a lot of mileage. They have a very small input bearing, & they will go bad frequently. If you put any power to them, the cluster gears will fail. Do yourself a favor & find a different OD trans.

Lonnie

 

[dyeager535]

I saw one of the 4WD 6.2L/4 speed OD trans in the wrecking yard, the tranny hump/shifter setup was very bizarre.

I would *think* that with an anemic 6.2L (IE no mods) and driven conservatively, the light OD truck trans should hold up ok. I suppose in a 2WD you could probably get by with a car transmission (80's camaro maybe?) which should be more prevalent, cheap, and light than the NV4500. Assuming of course if you don't mind cutting the floor up, and a suitable shifting arrangement could be made up.

I pulled an honest 20MPG over 80 miles yesterday, (GPS confirmed my speedo is less than .5MPH off 60MPH) but probably half of that distance was down hill, the rest flat.

 

[80' 427]

My grandfather had one of those 6.2 diesel od manual trucks with a 4x4 and 3.08s on the interstate 26 mpg. Of couse every time he pulled a trailer it broke a transmission.

 

[Slapperbar]

Ever think of a NV4500 behind it?

 

[1-tonmudder]

A NV4500 would be the ticket,but I don't have one.I'm looking to spend less on this than what a 4500 alone would cost.That's why I'm using the extra part's I have around.