So the 260 Delta cam any one know the rpm the cam start making torque .? LET ME TAKE A GUESS WITH 260 Dur. WITH 9:5:1 compression sohc,header prime Mary tube side1 1/2 anything larger you will lose low end torque, how about 1500- 5252 rpm even with S-40 from a EX CIVIC RATIO 4:26 Final drive ,YOU WONT SEE 15:90 et. How about 16:40 et ON A 500 light with a deep stage 205-50-15 street slick 18 psi no burn out .mmm. AT THE WED.NITE SONOMA RACEWAY LANE 6 COMPACT CAR CLASS !!!!