Block and heads dates
 

I've got a '70 LS5 with a block casting date of K12-9 and heads casting dates B3-70. Is it normal for the dates to be that far apart?

Less than 3 months?..That's not unusual.

OK, thanks.

Whens the build date of the motor??

Block stamps

In general I typically see big block cylinder heads cast before the block is cast on complete assemblies. I believe the cylinder head machining and preparation process was more time consuming than the block. Again, most complete untouched assemblies I have seen the blocks are typically cast after the cylinder heads by I'm going to say a couple of weeks. Was that the norm, I don't know, its sure what I see most often. could heads be cast after the block, sure they could, but they would have to be before the final car assembly and I would think in fact no later than the engine block machine code.

I'm still trying to learn all of this date and code stuff, but if I'm reading this right the build date on the block is Feb 13 and the casting date on the heads is Feb 3?

Block casting date of K12-9=November 12th,1969.
Heads casting dates of B3-70=February 3rd,1970.

Your[now my!] block is fairly early[cast date wise] for a First week march Arlington build....there fore the heads more than likely will be after not before the block. Its the same for many yenkos. I have 3 may yenko motors with May 69 stampings for June built cars,the casting dates on the blocks are dec 68 and jan 69,and on two the heads are march and april. I wouldnt suspect that the heads in these instances would be prior to the block,unless it just so happened that a block that was sitting around for months would be matched wioth a set of heads that did the same Just my 2 cents

Am I right about the build date on the block being Feb 13, or am I completely off?