Assuming your car is in good working order, NADA Guides suggests an average retail of $2,725. This quote is for a two-door, hardtop 1971 Ford LTD. If the vehicle was in amazing shape, NADA Guides quotes $4,656.
Depending on the condition of the 1971 Ford LTD value varies from $1500-$5500. If it is a completely restored LTD and there is a buyer that is very interested the price of a collector care is priceless and some are willing to pay anything. The average going rate is about $3000.
I would need to know what shape the vehicle is in. If it's junk you'll only get money for scrap. If it's in mint shape, many thousands from a collector.