[Jac Mac]

Fords theory was that this changed the way the main bearings were loaded.The one thing that the 13726548 order does is shift the consecutive firing cyls to the front of the LH bank- ie in the 15426378 they are 7/8, on the other 5/6. this can /does cause a bit of a problem with cooling in the two front cyls as they receive the cooler radiator water first and I am sure that many nascar folk used to reduce the comp ratio/ and or the ign timing on that #5 cyl in order to address this. From memory it was a case of that #5 cylinder running less effective clearance due to the cyl being cooler and the piston running hot with mixture being lean also partly due to #6 getting first bite at the cherry on a single plane intake. I dont ever remember having a problem with the early 15426378 order and in fact the only 'good' cams we could get back then were of that type. Also note that the FE & 429/460 all use the early order.