Can the #4446 (item# 50202) Be Equipped for SMOKE?
It is probably possible, but would probably be difficult to accomplish and not worth it for the ultimate end result you will achieve. If you want one with smoke, I would advise buying the Bachmann Plus version on ebay or elsewhere as it would already have the smoke and you would not need to modify it for the smoke install or for DC operation as it has no decoder.
Here is a link to one on ebay for $22 shipped so far, expect to pay about $40. http://cgi.ebay.com/Souther-Pacific-Daylight-4449-Steam-Locomotive-4-8-4-/320667709048?pt=Model_RR_Trains&hash=item4aa948ee78 (http://cgi.ebay.com/Souther-Pacific-Daylight-4449-Steam-Locomotive-4-8-4-/320667709048?pt=Model_RR_Trains&hash=item4aa948ee78)