Re: Cleveland or Windsor firing order?
The story I heard a long time ago was that when ford developed the 351W and used the old 221/260/289/302 firing order the the 351's #1 main bearing didn't like it, cylinders 1 & 5 and then shortly after 2 & 6 firing one right after another. so they changed the firing order. The original 5.0 HO motors used a 351W marine performance cam so they got the same firing order as a 351W. I would run the newer order, wider selection of cam grinds.
70 Maverick Grabber, 5.0 (Perf. RPM heads, RPM intake, FiTech EFI, Comp XE266HR roller cam, EDIS/Megajolt ignition, long headers), T5Z w/Steeda TriAx shifter, 9" Trac Loc w/3.89:1, 31 spline axles.