How can I find a blower motor for this Coleman gas furnace.

Take the motor off anf take it with you to motor shop,, they will match it

You could try here also. Link below.

Coleman / Evcon furnace replacement parts | Mobile Home Heating & Cooling parts and accessories (calefaction) | Mobile Home Parts - Magic Mobile Home Supply, Inc. (http://www.mhparts.com/coleman-evcon.php)

Here's a second link with direct information. Not sure if the best price available. Always call to confirm correct part for your application.

BestBuyHeatingAndAirConditioning.com 1/50 H.P. 115 Volt 3000 RPM Inducer Motor (Coleman Evcon) (http://www.bestbuyheatingandairconditioning.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=MOT79953&Category_Code=m-coleman)