If you want to put a Hemi in a "2-w.d.",Dakota,There are a few things you will need.Start with a cutting torch or cutoff wheel. A welding machine, a Saws-all, and that tool box full of tools.Dodge likes to use Metric and s.a.e.tools,not just one.
Pull the old motor, from here you have a choice depending on how much experiance you have fabricating steel,and how patient you are.You can either notch the cross-member or remove the oil pan and rebuild it.I notched my cross-member.I took all but three inches out of the back of it.Measure the oil pan and that's how wide the notch should be.
Next,measure the notch and re-support the cross member by welding steel accross the back and sides of the notch.I used 1/2" steel.It's solid.
Paint or undercoat the serface to prevent rust.NEXT I cut the motor mount purches off the frame.Grind smooth,You can use the same purches for the Hemi.
I installed the motor mounts on to the motor Leaving the bolt with plenty of room to install the purches once it's in the truck.My tranny is attached to the motor.Install the motor and tranny together if you can..It's going to be a tight fit going in,you have to have a floor jack under the tailshaft of the tranny.
Once it's in bolt up the Tranny cross-member,but don't tighten it all the way,bolt in the driveshaft.Now you want to move the floor jack to the oil pan and align the motor in it's new home.I did this by measuring the drive-shaft from the frame to the drive-shaft in the rear,then get the same measurement in the front behind the tailshaft.Once it's where you want it,and right up and down.bolt the purches on the motor mount.You will have to cut some off to get the right length from the motor to the frame.Tack Weld the purches to the frame,top and bottom. Lift the motor just enough to get to the purches and finish welding them.Drop the motor back down into the slots and tighten the bolts. Then Tighten the tranny crossmember bolts.RE-Measure everything and make sure nothing moved,Now you have a Hemi-In-a-Dakota.
GOOD LUCK.I'll try to put some pictures on here,But if you don't see any Write me @-firstname.lastname@example.org I'll send you some or answer any questions you have....