Turn it clockwise to retard it. Counter clockwise to advance it.
If this was not your question then asked it again.
On the front of the timing chain cover, drivers side towards the top of the harmonic balancer.
6 or 8 drgee
There is no timing belt on a 305 unless it is an aftermarket belt drive system.
Top Dead Center
6 degrees BTC
same as a 350
The easiest way is to look at the Harmonic Balancer. The 305 has a wider thicker balancer than the 350. Pus the timing tab on a 305 is located ON the timing cover and the 350 is bolted on the with the cover bolts. Riky9
8 degrees.
6 BTDC
counter clockwise.
32 degrees
Computer controlled and not adjustable