New to the board so forgive me if this has been asked before.
I am going to put a '92 12 valve cummins into a 94 diesel suburban.Can I use the chevy tranny without much bother and will I need to do any fab work on the frame?
Thanks
Gerry

 

My uncle has a 4bt in a 93' surburban and it still has the stock tranny. You just need to find the right adapter plate. I think the oil pan had to be modified to clear the front axle. I don't think the frame is modified at all on his. You may have to do some suspension work to hold the 5.9 up though.

 

you just need to find a cummins to GM adapter plate... they came behind most 4bt cummins engines in bread trucks because most of them had TH-400 trannies. or 4spd trannies

i hope you're not gonna put a 4L60E behind a cummmins... BOOM

In 94 the trans is electronic, that will not work behind the cummins because there will be no electronics, you'd have to buy a stand alone controller to run the trans and they're expensive.

 

I thought about a turbo 400 with a US gear overdrive.
How does the Alison tranny work in this app?

 

Like Brandon said, the 4L80E is electronic and is going to need a controller.

If you are going to turn the Cummins up, the trans will not be happy. Sure, those things will hold a 454, but we are talking close to double the torque here. Stock it will be OK though.

 

Which Allison?

I'd recommend a built 46RH or 47RH over a TH400/OD combo. Even a built 400 is going to be trouble.

 

I beleave the 93 has the IFS front suspension , we did one with a 4" lift , stayed with the stock trans but had it beefed up . we had to go with a 2 core rad and ran electric fans to give us a little more room since that adapter pushes the motor forward in its mounting position .

 

Yeah a 47rh would be great. No computers. Or a 5-speed!

 

Find a 47RH. The retrofit 4BT's rated at 105 hp & 275 ft/lb torque generally churned up the insides of a GM TH475 in less than 100K miles. Using the Dodge components will generally cost far less than using any GM transmission.

 

I am gonna turn it up a little.Probably up to 250 hp.How does the Dodge tranny fit in the tunnel?
If I use a nv4500/5600 I will have to change the dash and the steering column along with mounting pedals and cutting a hole in the floor next to the 4x4 shifter.
I have a buddy who wants to sell me an Alison which was behind an International D466 in a 2 ton truck.Have not seen it yet and I do not know what model it is.

Thanks for all the help

 

It's probably a 545, it won't fit the tunnel and it doesn't have OD. Not a good fit for your application.

 

I also have an 89 3/4 ton 4x4 Sub.
Is there a preferred conversion?Which combo is the least painful?
I want to be able to tow occasionally but mainly a daily driver.
Thanks

 

I think the solid axle on the '89 will be happier with the weight of the Cummins sitting on it. But the '94 does have better creature comforts and ride.

As far as fabbing mounts and bolting it all together, I don't think either swap is more or less complicated. Pick the truck you like better is what I suggest.

 

Thanks much.I think I will use the 94 because of the creatrure comforts.Will I run into any trouble with the a/c or have to notch the frame?
Would it do any good to use a 1ton front suspension.Will I need an extra fabbed cross member?

Thanks

 

I picked up the suburban yesterday.
Its a 94 diesel 4x4 2500.
Now I need to find a 12 valve.
When I buy one should I try to buy the complete truck or is the engine enough>
Will the NV4500 from a 1994 chevy 1 ton bolt up to the cummins?