Ok, I'm about to pull the head on the 300 here shortly to have it sent to the machine shop for some work. I was looking for a head gasket set at work and come to find out, '91 was a split year (apparently different valve seals, at least what I've gathered). There's a set to 2/??/91 and one that's 2/XX/91 and later. I can't tell what month it was made by looking at the truck as the truck is an '87 and the motor is a '91. I don't have the truck the motor came out of so no jamb sticker. Is there anyway to tell by the casting numbers on the block/head?

 

If the casting number starts with an E, it's from the older engine, pre-91, and it if starts with an F, it's a 90's. I believe the casting numbers jumped from E7 to F1, but I might be wrong.

 

unless Ford has changed its parts coding, thats right. F is 90's, E is 80's, my 63' has C's stamp on parts. I'm guessing 2000+ models are now G.

 

Thanks alot for the help guys. I'll check them when I pull the head and post up with what I find. Don't know if I'll be able to pull the head now this week or not with this snow/ice.