Slant 6 head interchange: 1975 head on 1969 Block?

Hey,

I bought a 1969 Valiant and the 225 head is junk, cracked and burnt valves.

I found a 1975-78 225 Head casting #3698447 on Ebay rebuilt with valves from a business for $210 shipped.

The guy at the shop selling it said I need to check to see it it will fit my block. He said my engine is earlier model. When I take out the spark plugs it has tin tubes surrounding them. He said to check if they are "large tubes"

The head they are selling doesn't have tubes? I don't get what I need to check. I bought a Haynes manual that covers 1967-76 Dart & Valiant 6 cyl.

Will this head work on my block is the question?

Thanks,