Stamped block numbers below head

[str12-340]

I'm looking for some information on the stamped numbers just below the head on an engine we are working on. The block is a 1971 360 casting and we think it is a Mopar Performance crate engine (early 300hp?). Anyway the numbers are HW560R3694. Across the number 5, at a diagona,l is stamped K-4 over the original number. Does this sound familiar?

When we took the Mopar aluminum dual plane intake off, it was clear that the heads and manifold had been gasket matched. Would Mopar performance have done that to a crate motor?

 

[Rocky_JS]

Think it should be HW(3)60R3694(XXXX)

H = 1972 engine model year
W = Windsor engine assembly plant
360 = cid
R = Regular fuel
3694 = date Wed, September 8, 1971
xxxx number of engine built that day to yours.

Are there letters/numbers midway across the right oil pan rail?

I would say from this information it is a 360 production engine.

 

[str12-340]

My understanding is that at some time MP used seasoned blocks to build MP crate engines so the production block was to be expected. What I can't figure out is the K-4 stamped over the number (which is why I couldn't make out the 3 in the sequence)

Thanks for the help!

 

[crackedback]

Look about here on the block. If there are any numbers stamped, not a crate engine.

 

[Rocky_JS]

In 1974 they were stamped K or 4 for the year '74. I don't think it relative here.
It could very well be, and probably is, an engine re-builder stamp. As many put their own stamping on them to signify it is theirs and to keep track of what belongs to who.

My understanding is that at some time MP used seasoned blocks to build MP crate engines so the production block was to be expected. What I can't figure out is the K-4 stamped over the number (which is why I couldn't make out the 3 in the sequence)

Thanks for the help!