Head casting numbers questions

[Dodgeguy44]

I have a 1976 Dart Sport 360 (4006830-360-5) with 2.02 valve heads one casting numbered 3418915-F and the other is 34189 5C. Are these the same heads or.......? I have looked through casting lists and haven’t found the second number. Where the 1 should be there is nothing and are F and C different?

 

[toolmanmike]

The 1 is probably just missing in the casting. Should be the same head.

 

[Marcohotrod]

3418915 - 1970-1972 - 340/360 J head . leak for casting dates - month (a letter) day , year - 70 71 72.. 70 71 was 2.02, 72 was 1.88"

 

[Dodgeguy44]

The 1 is probably just missing in the casting. Should be the same head.

That’s what I thought as well just wanted to have you experts verify. They appear identical.

 

[Dodgeguy44]

3418915 - 1970-1972 - 340/360 J head . leak for casting dates - month (a letter) day , year - 70 71 72.. 70 71 was 2.02, 72 was 1.88"

I will look for a date on them. Interesting.

 

[toolmanmike]

The letters on the end may be batch numbers or even mold groups. Molds and cores wear out from use and are rebuilt and modified as needed.

 

[Dodgeguy44]

The letters on the end may be batch numbers or even mold groups. Molds and cores wear out from use and are rebuilt and modified as needed.

That is very possible. Thanks

 

[MerlinsMopar]

Build dates are based on 10,000 day calender as far as i know.

 

[Marcohotrod]

Build dates are based on 10,000 day calender as far as i know.

I think build dates are 10,000. casting dates are month day year