on my 1985 iroz 305 TPI it was on the fire wall in front of passager side little black plug in 2 half inches long with black wire with white stripe.
8 degrees.
On the front of the timing chain cover, drivers side towards the top of the harmonic balancer.
You could put a vacuum gage on the engine and time it for peak vacuum. A timing light is still better.
intake manifold is DIFFERENT for models 1985 and 1988
yes
To set the timing on a 305 Chevy marine motor, first, ensure the engine is at operating temperature and turned off. Disconnect the timing connector to bypass the electronic control module, then use a timing light to check the timing mark on the harmonic balancer against the timing tab on the engine. Adjust the distributor by loosening the hold-down bolt and turning it until the timing light indicates the desired timing setting, typically around 8-12 degrees BTDC for a marine application. Finally, reconnect the timing connector and recheck the timing to ensure it remains accurate.
6 or 8 drgee
There is no timing belt on a 305 unless it is an aftermarket belt drive system.
ABOUT 1,000
Top Dead Center
6 degrees BTC
same as a 350