1970 340 heads (non-T/A)

how far into the model year did left over "X" heads * 2.02"/1.60" (cast #2531894/part #2531902) get used?

how to ID an authentic "U"/"O" head * 2.02"/1.60" (cast #3418915/part #3577053) used for a '70 model year car?
were there other letters used "J"/"Z" in '70?

when did the "360" casting start to show up on #3418915 heads?

I have a 70 340 for sale and it has O heads with 360 cast into them. The block was cast 11-17-69 and I forgot when the heads were cast, but they were close to the date of the block. I will check it again tomorrow and let you know!

VIN #?

I'll get that too...

AFAIK, 915's were always 360 heads. I've never seen an O, J, Z or U head with anything but 360 cast into them. Also seen 587 J heads with the hardened exhaust seats in 73. But I'm sure someone will prove me wrong..lol

Mid-December built 1970 Dart had X heads.

Probably more a function of what was on the shelf when heads were pulled. Inventory control then is nothing like it is now.

They all had the 360 (although Mopar never say never). It didn't mean the head came on a 360. I have never heard of an explanation from someone who would actually know.

R.

My late September built '70 Dart had X heads. My '70 Duster did not - unfortunately I don't know the build date of the Duster but it was not before early January of '70.

The heads on my engine were cast on 11-4-69 and 12-2-69 and have large "O" on them. VIN on the block is 0B423350.