[allenga]

I want to block coolant going to the heater core in the summer. I read the same amount of articles for each approach:

1. block the heater hose coming off the rear passenger head with a single valve.
2. don't block the heater hose, keep the coolant flowing with a bypass valve, so the coolant keeps flowing from the head back to the water pump.

I know the factory did it like #1 above then stopped.

What should I do on my 77 400.

Thanks