Looking for overdrive trani advice for /6, please help

Yes, I have the Clifford headers, dual exhaust. (the exhaust system has an annoyingly loud, howl between 45 and 60 mph) I bought the car about six years ago and the odometer said 97000 and was disconnected. There was not much of any history given to me about the vehickle. Its burning some oil, leeks oil from the oil pan and needs a motor mount badly all of which, I have been told, can only be repaired by by pulling the engine. Nothing else has really been done to the engine except that I also have a complete supersix set-up sitting in a large box in my garage from a 1978 donar car waiting for?? I have heard mixed reviews from many people here about whether I should keep the Clifford or go for the SuperSix. I'm not anywhere near the league you mechanics are in but I'm dying to learn! I do not have that much money to work with which is why I'm going slow AND asking you guys for help so that I don't have to do this twice. Thank you Slantsixdan!!
That's a negative ghost rider. Both mounts went on my dart at the same time about 5 years ago and I didn't know it untill we (me and dad) found that the clunking noise was the alternater hitting the passenger fenderwell due to the engine sitting on the k-frame. Two jacks (one for the car, one for the engine) and some hand tools had the mounts swapped and the issue addressed in about 4 hours. The engine never left the car.

Change your mounts ASAP before you do some perminant damage to your driveline.