The GT40 had a 4.7l engine which produced 380hp and ran a compression ratio of 10.5:1 http://www.carfolio.com/specifications/models/car/?car=2035
The MkII and MkIV came with a 427 with 485 - 550bhp and 475 - 535lb-ft torque and could reach a top speed of around 205. http://www.gt40spf.com/gt40-specifications.aspx The MkI and MkIII all come with 289s.
The Gulf cars, the most successful of the GT40's, Mk1's used the Gurney-Weslake 302cc, with about 540 horsepower, top speed of about 211.
Looking for a Used GT40 in your area?
CarGurus has 2 nationwide GT40 listings and the tools to find you a great deal.
Search Ford GT40 Questions
Ford GT40 Experts
Related Models For Sale
Used Cars For Sale