I think the AMC 4.0's are the best of them. Good torq, good hp, very dependable and durable, fuel injected. The slant's were reliable and fit under the hood of a car but only made 1/2 the hp.

As far as why dodge made the 3.9 instead of updating the slant, the dakota is the only reason I can come up with. Either the dakota was originally designed around the 2.2L and later they decided they needed a 6 cyl and the slant was too long or from the get-go they decided they wanted a shorter hood on the dakota. The decision making process at the time really boggles my mind. Here for the 1987 model year they debuted the 3.9 V6, carbed at 125hp which was less HP than either the fuel injected 2.2 turbo engines or the fuel injected mitsu 3.0 that were both available that year making 140hp. Then in 1990 the 3.3 V6 comes out at 150hp and the next year the 3.8 V6 comes out. They spent millions on developing the 3.9 really for no good reason and it wasn't any good of an engine anyway. I don't know if the fwd and rwd departments just didn't communicate and share or what because it seems like one big waste.

They didn't spend crap on developing the 3.9, go read the story at Allpar, it will answer your questions.

Chrysler pulled the plug on the Slant because they simply couldn't make it run clean enough for the tightening emissions standards.

Has already been covered and has a video attached in the first reply in case you missed it.

6 year old thread, but... you can use the Jeep 4.0 in a truck. In a car the deck height might be a problem if you enjoy being able to close your hood. If you are keeping it stock, the Jeep efi system is easy enough to dissect and transfer over. Transmission selection would rule out stock mopar transmission however there are other swap options that would work.

Didn't see the link at first, all I saw was "Yes". So the megasquirt pairs with the jeep 4L components? Because I heard the ecu is the one thing that won't work for the slant adaptation, because it requires cam and crank sensors

Honestly, Knote72, I'd just find a 4 L Jeep donor and grab every scrap of wire, sensors, computer and injectors and adapt the whole thing over to your 225.

Nothing beats Factory.

Fussing around with that aftermarket crap is a nightmare and only seems to work perfect for one yahoo on some online forum. Everyone else (You and Me) waste alot of money and time trying to get junk to work.

I've got a programmer for the 3.8 L supercharged engines. let me know if you're interested. I can check to see what years computer you need.