ratherberacin

so I have this 78 2wd 1/2t shortbox. its a original factory big block truck, I spent a ton of money restoring it and its never been more than 50 miles from home. it has a very healthy love for gas.

so.........thinking dirty thoughts about going a 6bt nothing wild. First gen 2wd auto donor truck and swap it over, other than suspension upgrades what am I in for? have a 4.5"x5 bolt dana 60 so good there. will upgrade front springs has addco rear and factory HD front sway bars in it now.

is this going to bolt in or some fab work is going to be required? I know trans crossmember is different and what else?

am I going to hate all that weight? it handles good with the big block now but just no fun when you can literally watch the fuel gauge move.

talk me out of it....or into it. anybody else done a 2wd?

Ram_SRT-10

I did an 88 pm me if you have any question this post don't answer
https://www.dieseltruckresource.com/...d.php?t=303540

freight train

What a gorgeous truck. I wont say should or shouldnt but think it over. Depending on what options you want to transplant over you will have to modify your firewall. Would you want to run the stock steering column and dash or transplant the 1st gens? Eitherway it would be a sweet rig.

440_D50

2wd diesel center link has a dip in it to clear the oil pan, gotta use that.

Is your first gen intercooled? If so, it's easier to use the later dodge core support, cut the 78 buckets and stuff out, and re-weld them into the newer one.

Firewall clearance should be no issue. Steering should be the same. The gear box flange ends of the hoses are different though. have to have one made with the newer style at the pump, and the older style at the box. Or just cut it and use a compression fitting.

440_D50

I converted my 79 to diesel, just went through all of this and have pics. I used my 79 core support and made the intercooler and radiator work. That was the worst thing of it, never do that again. I'll cut and weld next time.

jstone44720

Look real hard at a 4BT. That would be a much easier life on room and fuel. If it just isn't right for you then it would be awesome to see a 6BT in that truck. You are right on the front springs of course, and shocks as well to keep it all from bouncing.

patdaly

I second this, they are initially more expensive due to rarity ( and everybody wants one....) but they have mucho torque, and pull my 79 GMC 4X4 3/4 ton like it isn't even there.

And it is relatively easy to double the HP/Torque anyway.......

About 800 Lbs versus 1300.

ovlo

i would vote for the 6bt. 4bt engines are rough little thing that will rattle your teeth out. unless vehicle engine bay size is a problem i dont see why anyone would pick a 4bt. 6bt is smoother makes more power and fits with no problem.

i currently work for a fleet that has a lot of step vans. 4bt and isb4 and i drive a 12 valve dodge every day. i would have no interest in a 4bt swapped truck 6bt is worlds better and the fuel millage is the same or better.

NE frmhnd

Personally I'd like to swap a DT239 or DT246 IHC motor in. They run a lot (wayyy lot) smoother than the 4B. I'd get a custom oil pan made though, they were built to be part of the tractor frame and have a big heavy cast oil pan.

patdaly

You know, I keep hearing that, but mine isn't any more objectionable than my 6BT. The 4 does move around a bunch more in the engine compartment, but it doesn't translate to the body.

Do yours have the old style dodge/chevy rubber mounts or do they have the fancy isolationer biscuit types? Mine is the old style mounts, perhaps that is the difference.