After getting a new timing chain some time ago, I found that my car (240SX 1989) was driving very slow and lacking power, after looking around I found that the timing was set correctly by manufacturer standards (ignition settings), but the car will still drive very unefficient and with lack of power. Which mades me think that the mechanic mess the alignment of the cams or something when he put the new chain together, Is there anything I can look inside the valves when I replaced the valve cover gasket this weekend??? (Is leaking so I will opening the cover anyways...)

What will tell me it anything is out of place or alignment, ....

I just been setting the ignition by "feeling" and driving that way for quite some time.....and works fine so far.

thanks!