The 2003 Ford Mustang's engine produces 220 ft-lbs. @ 2750 rpm.
1968 Ford Mustangs are classic type cars. They are not going to be found on used car lots. The best places to search for these are going to be on eBay or at Auto Trader.
There are a number of sites where one might find a 1973 Ford Mustang to purchase. Listings can be found on sites such as Cars For Sale, eBay Motors and Autotrader. One can also check the local classified section of the newspaper or sites such as Kijiji or Craigslist to see if there are any available.
Research has shown that there are a number of options available for purchasing parts for a 1966 Ford Mustang. These parts can be found on eBay, CJ PonyParts, and Dallas Mustang.
According to one of Fords websites :
For a 1968 Ford Mustang 5.0 liter / 302 cubic inch V8 engine :
( the spark plugs are gapped at .035 inch )