Ok, everyone knows LS1, LS6, LS2, LS7, etc.
What about all these L33, LM7, LM4, etc codes?
Does some kind of cool matrix exist to decode?
I'd be curious of size, alum or iron, source, etc.

 

L33 = aluminum 5.3L truck motor
LM7 = iron 5.3
LM4 (maybe you meant LR4?) = iron 4.8L

 

LS1 = 5.7L aluminum block from 98-02 F-bodys
LS2 = 6.0L aluminum block from ALL TBSSs, C6 corvettes, 6.0L SSRs
LS4 = 5.3L aluminum block from latest generation Monte Carlo SSs and Impala SSs - (FWD)
LS6 = 5.7L aluminum block from C5 Z06 corvettes
LS7 = 7.0L aluminum block from C6 Z06 corvettes

LR4 = 4.8L iron block from 99-current GM 1500 fullsize trucks/suvs
LM7 = 5.3L iron block from 99-current GM 1500 fullsize trucks/suvs
L33 = 5.3L aluminum block from 99-current GM 1500 fullsize trucks - limited to ecsb 4x4
LQ9 = 6.0L iron block from 01-06 escalade, VortecMax trucks, VortecHigh-output trucks
LQ4 = 6.0L iron block from 01-06 Gm 2500/3500 fullsize trucks/suvs

L92 = 6.2L block from 07-up escalade, denali
L76 = 6.0L block from 07-up vortecmax trucks

 

Awesome, thanks! This info should be in a sticky somewhere.

 

http://gm-trucks.com/home/content/view/13/30/

http://lonestarthunder.com/m_rpo.php

 

LM4 - aluminum 5.3 in trailblazer/envoy.