There are a couple of things that are the most often offenders when this sort of job is done, Tibur.
When a distributor type ignition is involved, it is not at all uncommon to get the distributor out of phase. Sometime the engine will almost run this way, but it will be noisy, very rough, clearly something wrong.
Another thing is that modern spark plug cables are very easy to damage and the damage can't be seen. I read that you installed new plugs, but what about the cables?
And as you know, if you have crossed some of the cables onto the wrong plugs.....
You seem to be sure that cam timing is correct. This is important.
Vacuum leaks...a vacuum leak can made an engine run like the very devil. This can happen at hoses, gaskets, carburetor, etc.