What does an XXX or YYY or XX or YY stamped in the lifter galley mean? what are the differences?

 

On what engine are these marks? I've never seen them on any of my 302's! And come to think about it i don't think i've ever seen anything like that on any Sb Fords i've had.

 

These marking came into use with the 80's-90's 5.0 liter versions. XXX signifies a roller cam equiped HO (high output) motor (or Cobra)such as used in Mustangs, Lincolns, V8 Explorers ect. The XXX blocks used a roller cam with a lifter retaining tray and X shaped lifter lock downs. The XXX blocks are for more heavy duty applications too. I believe that the Y markings were used on non-roller cam motors such as used in police interceptor Crown Vics, Marquises, Town Cars ect. Variations of these markings probably help to keep track of different cam, block, and EFI intake design combonations. For example, truck 5.0's after about 94 had roller cams, but were still different from Mustang, Cobra and Explorer type HO 5.0's.

 

thank you.

 

Well no wonder i have'nt seen that most of my stuff is from the 60's and 70's.

Learn somthing new everyday!