Puff of smoke on accel
 

Hi guys have a few questions maybe you guys can make a suggestion on what it could be. I dont have access to a leak down tester which i think would really tell me all but this is the issue. I rebuild this engine about 1k miles ago. I just started noticing if im sitting at a light for a while and i accel normaly not punching it i see a bit of smoke. some times its alot more noticable than other times. Coolant level is fine. does not over heat at all. Oil level is pretty consistant but i do have an annoying pan gasket leak that ive done twice. I removed the pcv valve just to see if maybe that was the culprit but it didnt really change much. any other thoughts? Supposedly the head had new valve seals put in not long ago.
The only other thing i did was a valve lash when i did the rebuild. I did i think .07 on the ex and .06 on the IN. i didnt have the book and found that on HT. The other day i was cleaning the hood from underneath and noticed the picture said to do both IN and EX to .02
Could a loose valve lash cause some of the symptoms im exp?

It's possible. You also said the head has new valve seals which raises my concern.