L59 Z engine code and LM7 T engine code......difference?????

Anyone know what the difference is between these engines? They are both 5.3L.



Thanks

I think one is a aluminum block 5.3 with 295 HP and the other is cast iron 310 HP

Do you know which is which?

aluminum block motor makes 310 HP which is the L33 and the iron block makes 295 HP Which is the LM7 motor and the L59 Is the 295 HP Iron block that has the flex fuel option to run on ethanol

Both engines are aluminum blocks. The L59 (Z) is the 5.3L Flex-Fuel engine, and the LM7 (T) is not.

What year are we talking about here? I looked up 2005 on the GM Powertrain Website and both the LM7 and L59 are cast iron blocks.

http://archives.media.gm.com/division/2005_prodinfo/powertrain/engines/05_truck_engine_specs.html#lm7

//2000CAYukon