1987 D20 6BT Conversion

[ursusarticus]

I have a 1987 D20 ( 3/4 ton 4x2 pickup)with a 360 and 727 TF and I am considering swapping in a 6BT drive train I know that I will need to swap the rear axle and transmission. My biggest question regarding this conversion is, are there any firewall mods required? I know that I will need heavier springs up front. My biggest concerns are the firewall and all of the details. The intended usage is being able to tow a 30 foot gooseneck loaded with firewood or hay bales. The truck barley pulled the trailer lightly loaded from the Ozarks to California. After I did some basic tests I found a bad head gasket at least. This truck has always been torque challenged. This is the reason for wanting to do this conversion. I would like to keep the automatic transmission but which one will work best? I understand that the 727 will not handle the torque so I am relying on your pool of experience for advice.
Thanks guys

 

[Wayne M.]

Are you speaking of the Dodge B van? I'm real interested in this swap, but won't be doing it so I hope you can keep in touch on this!

 

[DVolk]

I think it will be too tight , there isnt that much room under the dog house on those , youd be better off with a newer 4bt

 

[ursusarticus]

I think I confused everyone, it is a 1987 4x2 3/4 ton pick up that I am considering repowering with a 6BT package. Sorry for the confusion guys.

 

[Wayne M.]

I think I confused everyone, it is a 1987 4x2 3/4 ton pick up that I am considering repowering with a 6BT package. Sorry for the confusion guys.

OK, sorry for lighting off the confusion, and welcome to the TDR.
First thing if you haven't caught on, is that the Dodge diesel pick ups are classified by generation. There are four. The first gen trucks would cover yours up to 1993. You are in the right place, but you may want to consider linking this in the first gen forum.
If you can find a donor truck, that would be the way to go. I'd say the biggest difference between your truck and a later diesel would be the electrical system, and if you wanted the '91.5 to '93 version, which is intercooled, the radiator support and related hardware. Regarding the trans, depending on how strong you want to make the engine, the lock-up version of the 518 might be the ticket. I urge you to consider a manual swap. Driving one of these with a stick is a real eye opener! I think the firewall is the same for all years.

There some real knowledgeable first gen guys here, and I hope they jump on.

 

[DVolk]

If you have the engine and transmission it will slide in no problem , to wire it up , just run the ignition wire to the pump and your good to go the grid heaters on a push button , the only thing you might have to do is add a set of spring over front shocks or get 1 ton springs , if you would have posted this a month or so ago i had a set of springs and tie rods etc .

 

[DVolk]

no firewall neds are needed if your doing to stay with a auto a manual you shouldnt depending upon buildate , 87 they changed back to hydraulic clutches , the rear end will live with a 60 in the rear , just treat it well