I balancer mark is not set to the timming cover notch

I recentley had my 4.3 vortec on my 96 blazer rebuilt.The head gasket was blown.It did over heat but heads are still fine.My problem is when I set the timming.I pulled the #1 spark plug out and pushed a rag in the hole.I spin the engine untill it pops the rag out.Check the balancer mark and the closest I come to it is about 5 in. off the timming cover notch. dots on the front gears were matched up by the mechanic,but can it be he put them on wrong.The rotor is also set to the mark on the cap which indicates the start of the firing order.My real problem is that,the engine starts up fine but is sputtering on idle and aceleration.Engine shakes a little.I really need some advise.This is my wifes vehicle and it has been down 3 months.Thanks

Look at your harmonic balancer sometimes they will spin on the rubber and don't line up. Watch when running and see if its noticable. If you put a timing light on the car what happens?

I have not tried the timming lite.So you think timming could be ok.It will start up fine but has miss.Kind of like when spark plugs are bad,but they are new.

Its in the neighborhood or it wouldn't run. It still needs timed check the balancer.