He is correct that you have a lot of options with that car.

We have rolled out of my shop a 39 plymouth coupe with stock frame, disc brake conversion, rack & pinoin steering, and a 3.9 V6 from a Dakota. We put about 8,000 miles on before it went down the road. We did the Dakota clip on the 39 sedan. We did a 360 with headers, 727, a disc brake conversion and an 8 3/4 with the stock frame and suspension in a 47 Plymouth coupe. We did a flathead 6 with OD, stock suspension, drum brakes on a 41 Chrysler sedan. A 35 Dodge sedan with a Volari clip, 318 auto, 8 3/4 we put over 70,000 miles on. We did Dodge trucks too, a 54 with an F,M,& J clip, 360 auto, 8 3/4. a 55 Pannel van with stock suspension with a hot 360 auto, a 50 mounted on an 80 4x4 frame, and currently putting a 77 frame under a 70 short box. Been a few dirt track Mopars thrown in there as well and several Mopar muscle cars. And that's just our stuff, not customers things. A guy can screw up a lot of nice cars in a little under 40 years of building them. Add in a 25 yo son also addicted and the car count jumps again.

After all that, its going to be very hard to beat the price of putting that Dakota under your $300 Plymouth. There is going to be some work that will have to be done, like the Dakota motor will have to be moved towards the rear, several inches to fit in the engine bay. You will also have to modify the Dakota frame in front of the front crossmember and come up with brackets to mount the cars front sheet metal and a radiator. That is all part of the fun. Gene