1984 2.8L V6: LL1 "CodeL" vs LC1 "Code1" ?

[pgtr]

Any good insights or details as to differences (or how to recognize)
these two 2.8L V6s?

All I know or have gathered is (for 84 Firebird):

LC1 "Code1" 8.4:1, 107hp, 145 ft/lbs, R43CTS plugs

LL1 "CodeL" 8.9:1, 125hp, ??? ft/lbs, R42CTS plugs

They can be differentiated by the 8th digit on the VIN but beyond that,
don't know much about their differences, internally or externally...

Oh and why the different heat range plugs?

Thanks