That's isn't a casting number, it's a engine ID number stamped in the block.
Pretty standard GMPP crate engine.
1= Chevrolet
M= Mexico
0519 3= build date. May 19 '03 I think.
ZZ4= 350cid,roller cam, one piece rear main seal, 58cc aluminum heads
A few different version over the years but generally a good crate engine. Up to 355hp/430tq depending on version. Check for a tag below the passenger side motor mount. Has it got a plastic timing chain cover or a stamped steel one?
-- Edited by DaveM on Wednesday 8th of August 2012 10:18:08 PM
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