Pulling balancer off of 6 cylinder questions

[72farmer]

I think it is a 250 I6 on my 63 chevy truck.How does this pulley come off?It don't have a bolt in crankshaft holding it on.
I need to put a valve in one of the heart hoses.To shut hot coolant off to core to keep heat out of cab this summer.Which hose do I put valve in small or large hose?

[Wrenchbender Ret]

Remove the damper with a puller that uses the 3 tapped holes in the damper. Do not pull with a 3 jaw puller on the outside of the damper. It will destroy it. It's a good idea to drill & tap the center of the crank for 7/16 fine thread bolt. If not clean the surfaces & heat the damper up a little to expand it. Use a high pressure lube & hammer it on with a big drift & large hammer.
Put the shut off valve in the small hose that comes off under the thermostat.

[GMDad]

The tapped holes in the balancer are 3/8-24 fine thread and don't drop it as you pull it off like I did and broke it.