There is no way to keep costs down on a project like that. You'll have $20,000 invested to just get the engine swapped in and the car running. By the time you finish the interior, do all the body work, wire the car, build a new dash that works with the new engine you'll have $50K in the car. If you want a fun car just go buy a new one. If you want to create something unique then do it, but it won't be cheap.

i envision a swap like this should include a person buying a totaled "whatever", that has a complete drivetrain, and use all the related components as required.
i believe this would be money well spent.

With a V8 8 3/4 disc brakes, my 68 cuda was 3070 so your motor should knock off a couple hundred pounds or in other words right in the size of a stratus or so, you'll have plenty of gidy up. The 904 will be just fine, they came factory behind some 245 HP 360s and the motor will not like being lugged down and if it turns 3000 so what? A 904 from an early 2.5 dakota should bolt up and work great. The later 2.5 from a dakota that is built off the Jeep engine probably has a different bolt patter. If you do really think you need OD than a 42RE can easily be built to take that but I am not aware of one with the correct bell housing. Were not talking and engine with a 3.5 or 4 inch stroke and boat anchor pistons so 3000RPM is no big deal. Use a computer from a manual trans car and it will function just fine with the 904. The 8.25 rear will be fine also, they came in 1/2 ton trucks and held up just fine.

I did a bit more digging and learned the builder is a guy named Richard, who owns (or is employed by?) a shop called Rides By Design, in Richmond, Illinois. I messaged them and learned the project is temporarily on hold due to being too busy with customer's cars. Here is their Facebook page, plus a few other threads I found:
turbo-mopar.com
turbododge,com



That's too bad; I could never spend that much.



That's actually a great idea.

You need to go look at the kind of work Andy does and you'll understand why it would cost him $20k to do just the engine swap. If you're willing to live with a lot less perfection and a whole lot more junkyard engineering and not farm out anything you do not absolutely need to then you can do it for a lot less.

There are several ways to build a hot rod. A down and dirty fun ride you can actually drive legally on the street doesn't have to break the bank, but it will cost some money, the days of a $2,000 hot rod are well over. A shrewd guy might be able to get a down and dirty hot rod to the street for $2,000, but he won't be driving it long before he is adding more function (and money) into the hot rod.
The more refined you get, the more is costs. A show quality custom build ride can get pretty expensive. Paint and body work is expensive, even if you can do it yourself. Gene