Hi Guys
It's been several years since my radiator has had any fluid in it.
I'm now about ready to start my 31 chevy .
Any tips ? what blend of fluids should I use.
Thanks
Stanman

I would put straight water in for a test run. If no leaks and everything is good to go, drain the system and put 50/50 water and anti-freeze.

Stanman
Chevy1937 has given good advice for 2 reasons (1) straight water is cheaper to replace if there is a leak and the lot needs to be drained (2) Some (fibre At least) head gasket manufacturers recommend plain water for the initial running to allow proper sealing.
Tony

I run straight water all the time. When I put my car away for the winter I drain the water and put two gallons of anti freeze in. Run the engine about five minutes to mix with any water that did not drain. Drain the anti freeze and save it for next year. In the spring I fill with straight water. It works for me.

There is some debate whether straight water cools as well, or even better, than a water/coolant mix but, that argument aside, using a 50/50 mix has notable advantages over straight water in the radiator. Water/coolant mix boils at a much higher temperature than straight water so topping off the radiator is much less frequent. Water/coolant freezes at a much lower temperature so a damaged engine is much less likely. Coolant has corrosion inhibitors in it to prevent internal corrosion to the engine that straight water promotes.

The anti-freeze also has lubricant for the water pump. I never go without it.

...never go without it...good idea ! ...And I recently purchased an overflow tank to retain that precious cargo...

On a sealed bearing water pump the only thing the anti-freeze or an anti-rust can lubricate is the seal in the water pump. I run 50/50 all year around in my cars. Modern anti-freeze has excellant anti-rust additives.