87 d150 questions

Hi everyone I'm new to this forum and dodge vehicles as well.I recently purchased a 87 d 150 with a 318 and auto, but running the vin it states w which from what I have seen means it was assembled with a 360. My problems are it smokes like crazy this started yesterday,back fired so bad it blew a hole in the flowmaster muffler the size of a football,and massive blow by I under stand most of the issues stem from whoever had it before me didn't take care of it,but today I put a new carb,fuel regulator,pcv valve,New oil since their was gas in it,plugs,wires and so on the back firing is mostly gone but the other issues linger.but what truly baffles me is with all the blow by, and what seems to be two dead cylinders at idle and smoking like a chimney this thing still will pull a trailer with a car on it at 80mph...I love it but don't know where to look /repair next....I have already done headers,new 40 series flowmaster, weiland air gap intake,and freshly rebuilt Carter carb and all gaskets...so any input would be much appreciated thanks.....

Try putting a new coil on it, could also look at the electronic ignition box as well. As for the blow by, only a true compression test will verify what the real culprit is. Hope this helps.

Until you do a compression and leak down test, don't put any more goodies on it.