This seems to be a major area of confusion and time lost during install or diagnosing as to weather the Cam is truely aligned properly.
There have been numerous threads over time that the OP said the Cam timing was verified to be correct (checked it 3-4 times) and after a 4 page thread and numerous days/weeks of unneeded diagnostics it turned out the Cam was 1-2 teeth off.
The Cam spocket has an oval slot in it that needs to be aligned at 12 o'clock centerline with the cylinder head.
The issue seems to be where is true centerline?
The cylinder head is on an 84 degree angle so centerline of the head is not 12-6, closer to but not exactly 11-5.
There are 2 parallel lines on the sprocket that should be aligned with the head as it sits on the block.
Problem is with the engine in the car they are extremly hard to see and with the engine in the car viewing the oval slot can become an optical illusion because you cannot view it directly at eye level.
Cam sprocket alignment is extremly important and will create all types of driveabilty issues, stalling, hard starting, lack of power, etc.
There are 40 teeth on the Cam sprocket so 1 tooth off on the Cam is 9 degrees at the Cam which would be 18 degrees at the crank.
The easiest way to verify Cam timing and belt tension.
1)Remove the upper cover and measuring around the top from bolt tab to bolt tab get a total reading then divide by 2 and mark that spot on the cover.
This will be 12 o'clock center of the timing cover which is also 12 o'clock center of the head.
2)Remove the spark plugs and rotate the crankshaft by hand clockwise until #1 cylinder is at TDC on a compression stroke.
3)Verify TDC by being sure the timing mark on the flywheel/torque converter is aligned with 0 on the timing plate.
4)The slot in the cam sprocket should be aligned with the mark you made on the timing cover in step #1.
5)The distributor rotor should be aligned with #1 cylinder on the distributor cap.
6)Realign marks and retension belt as needed.
7)Rotate the crankshaft 2 revolutions by hand bring #1 back to TDC as in steps 2/3 and recheck mark alignment.
8)If correct you can start the car before installing all of the removed parts to verify tension is correct as long as all electrical components and vacuum lines are connected.
A properly tensioned belt will ride in the center of the cam sprocket.
If it rides to the outside the belt is too tight.
If it rides to the inside the belt is too loose
The LONG LINE is center and where the Cam Sprocket Slot should be aligned.