This is an 1988 Cobra 350, not vortec, but great advice. I drained it all last night, it was hard to get the rubber plugs off the bottom of the manifolds, found out why, they had not been off in some time...had to punch through 1 inch of sand and gunk to get the water out. Drains in the blocks were better, but a little plugged. With this motor thats all I should have to drain, correct?
I may see if I can work the hoses off the manifolds, and put what straight RV antifreeze or regular auto antifreeze in it?
Or just leave it this way dry...air doesnt freeze...right?
Emailed seller, him and his friend bought a winterize kit online, mixed 50/50 rv .....but did find out previous owner always had the local marina winterize it, so this was the first time he had winterized....just glad I caught it. The antifreeze just seemed to weak....
Also found out their are different testers for rv antifreeze and automotive.....