Hey everyone, this is my first post on here but I need som help. I bought a 88 dodge Dakota 3.9L V6 for a steal of a price from a friend who intended on doing a “race build” with it. That being said sodas the truck is rust free and stock other than the suspension being lowered 3 inches.

What I want to do from here is swap the engine for something with more power. I was thinking about putting a 318 into it. To my understanding the stock automatic 904 transmission should bolt right to a 318 as long as it is from a 65 or later. I can get a 318 already mounted on a 904 from a 71 Dart. Will I be able to use my existing drive shaft, and transmission mounts and just buy 8 cal engine mounts from a 94 Dakota or is this going to take more fabrication and or other things I’m not seeing?

 

Welcome to the forum!!!

FWIW. you may want to look at this site, and others like it. http://www.manciniracing.com/192wddakensw.html If your set on using the older 318

I assume yours is 2wd.

I have been planning a V8 swap on my 87 for quite a while. But mine is 4wd.

Here is what I believe is true.

In the long run, it would be much easier to start with a magnum V8 (I prefer the 5.9) , get a edelbrock 7577 manifold, and whatever ignition you want. The magnum has the mounts in the right place to bolt up to your existing engine mounts. Also, with the serpentine belt system there is just enough clearance to clear the radiator. The v-belt system will not...... Then you mount a pusher electric fan in front of the radiator.

Do a search on this forum. Look for ragged89 and robertmee. They both have posted lots of good information on V8 conversions

Good luck!

 

The 318 LA block will mount to the 904....and if you put the engine in the same location, the drive shaft and transmission mounts are the same. However, the 318 LA with the long water pump snout will not fit inside the radiator. Even without the mechanical fan, just not enough room. Check out my build thread on my 90 and you will see what I mean. I ended up going with a 94 front end which gave me enough room. The other options are:

1) to do like the Shelby 89 and move the motor mounts and engine back against the firewall. But that requires custom mounts, and will move the location of your transmission mount and shorten the drive shaft.

2) to make a custom radiator that tucks inside the radiator core with a fill spout on the side. Check out Siggie's build thread and that's what he did.

3) Install a magnum 318 with a serpentine setup...the water pump is much shallower and will just barely clear the radiator.

4) Custom machine the LA water pump snout shorter, which will require custom pulley's on the crank and alternator to line up.

 

The motor mounts won't match; by 1994, the Magnum used the same mount points as the 3.9 (ALL 3.9/5.2/5.9 Magnums used them); that 1971 Dart 318 uses the "elephant ears" and will need an adapter.

I'd suggest, instead, starting with a 5.2 or 5.9 Magnum; you can buy LA-drilled Magnum heads (and there are a few carbed Magnum pattern intakes!), and that will bolt up to the frame.

robertmee covered some of the other considerations; with the Magnum, you can start off with the shorter water pump and closer accessory drive, and with a pusher fan in front of the radiator, you SHOULD have clearance.

If going Magnum, consider also a 42RH/44RH/46RH (in increasing torque capacity); tapping into overdrive and lockup is just a vacuum switch, a pair of pressure switches, and some wiring away for those (PATC has a kit, but their description includes what all's in the kit and how it all interconnects).

That's all my opinion, of course, save for the motor mount problem.

RwP