Why exactly did Ford use the 351 firing order on the 5.0 HO's, instead of the regular 302 firing order? Was there some sort of advantage to it?
I remember hearing it balances the engine better and creates a slight increase in power. The only difference between my 5.0 sitting in my garage and my cousin's 85 Mustang GT's 5.0 is the cam has higher lift and some duration, but his idles way better and smoother than my Cougar did back when the 5.0 resided under the hood.
Their are many theories. Read this:http://bbs.hardcore50.com/vbulletin/showthread.php?t=22729&highlight=firing+order
James