Put some new plugs in it.
If that doesn't work then, really no insult intended here, but if you've got a Chrysler and don't know how to work on it yourself, use it as an anchor and buy something less awful. The cost of getting an engineer to look at it will exceed its value by the time he's finished reading the name on the cowling.
true when it comes to the older engines unless you can fix it your self then it isnt worth thinking about engineers as nos4r2 said put your money towards a better engine and sell your one for spares or repairs youl be amazed how much you will get for it on flee bay if some one wants parts for there engine
hope you get sorted :sun: