Next up is our 'block gambler'... He shots... It's a.... cracked block! Why? Draining is so easy, why would you even think about taking such a risk?
You are relying on a FORECAST of the temperature... It's been know for them to be quite a way off. Let's say they forecast 26... You think "Hey, 26 for a couple of hours. I'm cool" But they get it wrong, and the temperature drops to 22, and is there for about 4 hours (it happens!) and doesn't rise back up beyond freezing for 10 hours... I'd say you have a block replacement job coming up. Much easier, and for peace of mind, jump up in the boat, knock the drains out, poke 'em with a stick, sleep easy...
I tend to get nervous about not winterizing when the temps are forecasted to get near the freezing mark. To Chris' point, you do not know how accurate the forecast will be and such, particularly if you are in an area that tends to deviate from the forecasts.
This year, I actually made a special trip to my boat to drain stuff, when the forecast was to go into the mid-30's.
Oh great. It's like I started the great oil debate on a Harley Davidson forum. Sorry. I was REALLY just curious.
I forgot to drain my 1980s 5.7 last year (which was kept in dry storage, un-insulated metal building) during what was the coldest winter in 60 years here. No problems whatsoever.
I don't drain my block as I have a 1/2 closed cooling system. The manifolds and heat exchanger DO get drained and I keep mine in a heated garage! Better safe than sorry!