I have a Clifford 4.0 head and a 4.2 block . Short block has forged pistons , molly rings , Comp Cams Extreme Energy [email protected] & [email protected] with .493 and .513 lift . I also have the Offenhauser aluminum intake 4BBL manifold with a 600 CFM Holley vacuum carb . Compression is at 10.2-1 ( pump gas ) . Headman headers and Flowmaster Racing 1 chamber 3 inch muffler . I have dynoed this combo in California on a dynojet dyno . This is rear wheel horsepower and torque figures , 289 HP and 301 LB FT of torque .