depends if the motor is rated for continuous duty or not. I'd wager a furnace blower motor is not. Probably rated for a 15 minute duty cycle. depends if the motor is rated for continuous duty or not.

Don’t guess the blower size, and be sure to verify performance after installation.” Beaulieu said he’ll replace the motor with an OEM motor depending on the age of the furnace. “If it’s less than 5 ...