56 block numbers

[Don B.]

Hi everyone. New to the board but have been a member for several years. Have 2 questions
1. Have a 56 block casting # 3720991 Date code C146. The number stamped on the pad is 0370917F56. No engine ID letters. Is this a replacement short block?
2. Have a set of heads casting#3731539 date code C146. These have been reworked. Ported, 2.02 intakes, exhaust ports modified etc. There are no "humps" on the castings. Is this possible or were they ground off to covert up the fact they are the 1539 castings? Stock car racing??
None of this is for sale.

Thanbks for your help.

[Edward M.]

Re: 56 block numbers

Ah, 56 engines, my favorite subject....

0370917F56 decodes as follows"

0330917 = engine sequence number
F = Flint
56 = year (1956)

Now, it seems like you are missing a suffix code, like you said.

Is the engine pad painted right now? Sometimes the characters are faint. Take another look. If it is painted, remove the paint and look.

The replacement 56 short blocks that I have seen have no numbers at all. Don't know what this might be.

The 539 heads should be 57 powerpack heads, so the date code of C146 doesn't make sense. Could you check that again please.

[Lynn H.]

Re: 56 block numbers

Don,
As Edward stated dates do not make sense, is it possible the letter is other than a "C"? As far as the casting ID symbol, they would not have had the "camelback" or "double hump" symbols, those did not come out for a few more years. the correct symbol for the 539 should be a "pyramid".
Lynn

[Don B.]

Re: 56 block numbers

Thanks for the replies. Date code on heads should have been C77. Also has a "13" under the date code which appears to be a replace ID on the pattern (screws heads visible). I will have to take a magnifying glass and check the pad on the block. There is no paint on the pad and then block has been repainted.

[Mike M.]

Re: 56 block numbers

are there broach marks on the pad?mike

[Don B.]

Re: 56 block numbers

Broach marks are not visible on the stamp pad. In addition, the last digit "6" is barely visible. I suspect the block was decked and the missing two letters were milled off. Thanks for everyone's help.

[John N.]

Re: 56 block numbers

Broach marks can be faint or almost impossible to see on a real undecked 1956 block. Post a good quality picture and you will probably get a correct answer here.
Regards