Here is my expierence built (manual valve body and all) c-4's would last me about a month.....stock c-6 with a b&m shift kit still good 1 1/2 years later. I run about .3 quicker with the c-6 but I attribute that to the fact I put an 10 in convertor in with it verses the 11 in I had in the c-4 actual weight gained after transplant was less than 50 pounds and have watched a drag (hp to turn the output shaft) comparsion betweeen a c-4 and a c-6 they have the same parisitic loss. Now the thing I am sure to get the flames started with but all the sub 10 sec. fords I know either have 2 c-6's one for back up at the track or 3 c-4's one to run one for backup or one being rebuilt after only a weekend of racing verses getting a season or more out of a c-6. With that I wish you luck on your decision.
------------------
67 Falcon Small Block,C-6,3.25 spool, best ET to date 13.2 tore that motor down and found 3 spun rod bearings and 2 flat lobes on the cam hoping for 12's with the same setup just fresh same cam grind and all.
|