only if you drained everything first and then ran the af thru it. easier to just flush, fog, drain, reinstall the plugs and pour it into the engine and manifolds
If you don't drain first, it will go straight out the exhaust for the first 10 minutes of run time until the thermostat opens. Simply attempting to suck AF thru muffs will result in a cracked block over winter.
Drain the block, manifolds and lines like it says in the manual, then if adding PG AF makes you feel good, use a funnel to add it via the lines at the t-stat housing
Open the drains . . . just to be sure. The AF running through the engine is a 'diluting' process, so what remains in the block and manifolds after sucking 4-5 gallons of AF is partially mixed with water and will freeze at about -10F
I just drain my 5.7l and leave it. After draining the block I take the big hose off the water pump and the intake and output hoses off the impeller housing. Crank the engine over with the lanyard switch off for a split second to shake any water out. This is only for the cooling side. It is a good idea to change the oil also. I remove my drive every couple years to take care of any maintenance that might need done over the winter also.
