Engine ID/Help/Opinions on my 3970010

[Steven H.]

I thought I had an over the counter none stamped 3970010 or maybe decked, but I was leaning toward over the counter because of what looked to me to be factory type broach marks. I also thought it was a June cast 1973 %F73; now I know that's not the case, so what do I have here?

Two things to note; all other GM parts left on the car have checked to be possible correct L46 with the exception of the fan blade still in question. I had a deck height of -.023 to the Sealed Power .040 over pistons; if I am measuring and representing deck height correct.

Today I found this HX VIN stamped engine and in all likelihood untouched engine in the VIN correct car but it has an I24 where I had placed mine at June 1973, obviously way incorrect on my part and putting my engine back in the running for the original motor?





And then the engine pulled out of my car:









Opinions, facts, questions, help of any kind?

Note: Duplicate post on Corvette Forum

[Cecil L.]

Re: Engine ID/Help/Opinions on my 3970010

If I understand your post correctly, the blank pad on your block does not have factory broach marks. The swirl marks are typical of a decked block. The Casting date of your 010 block is June 7, 1973. I don't understand your point about the VX engine being cast Sept 2, 1974 and how that relates to your block. what is the date you are looking for?

[Steven H.]

Re: Engine ID/Help/Opinions on my 3970010

Cecil

The entire point is how did a VIN correct 1969 block get cast in 1974? It didn't.

This thing about these cast dates is way off base; I'm not even sure now if F73, I24, or any other series has anything to do with the date. Also check the issue with the M motors.

Some of the swirls are from my 3M pad on the grinder.

[Cecil L.]

Re: Engine ID/Help/Opinions on my 3970010

Ok, looking closer at the pic of the casting date on the HX block, I think if you clean it off, you will find I-24-8 instead of I-2-4. That would make sense as a 69 engine block cast on Sept 24, 68 and assembled Oct 30, 68.
As far as your block casting date, the only way that would make sense is if the 3 in the F-7-3 is really a poorly cast "8".

[Steven H.]

Re: Engine ID/Help/Opinions on my 3970010

Cecil

Your right, I think now that you said that I do see an 8. The screen at work where I originally posted this does not have the clarity of my home 1080; reading the threads on the M castings didn't help me, but I stand corrected in that the dates apparently do hold true.