I want to do an engine swap in my 1999 dodge 1500 for horsepower but I’m not sure what I should even start looking at I have a 5.9 in it rn

 

5.9 is the largest displacement engine the 1500's came with. Being it's a 99 though, the PCM is programmable, so, you could do some mods, and get a custom tune.... Question becomes, what do you want to do with your truck? It will never be a race car..... If you want to do 'truck stuff' with it, then you want bottom end torque, not top end horsepower. (you can't have both....)

 

Why do you want to swap the engine?

 

Twin turbos would wake it up!

 

I think I want to put a hemi in it but then I don’t know what transmission to put in it either or if a hemi would even work?

 

It *can* work, but, it is a LOT of work..... There was a thread here a few years back of a members hemi swap..... there were a LOT of issues, and I think he sold the project before it was done.... You would likely end up spending less money building a healthy 5.9, getting a tune, and installing that....

 

I was thinking of putting a hemi in it but I don’t know what transmission I would need to put in it too ?

 

Whatever came behind the hemi...... Rumor has it though, that it will bolt to the 46RE trans, just one hole doesn't line up, or some such. RUNNING the engine is the fun part.

 

If you use the 46RE and a hemi how are you going to control the trans? The pcm does it, I would get a hemi with the trans then swap both. You will need the pcm/wiring to run them. Another option is bore/stroke the 5.9 to a 408. With mods you will have more hp than the hemi.