I was reading the 1977 mk2 escort factory workshop manual and noticed that there were 2 variants of the 2lt pinto a 8:1 and a 9:1 compression ratio versions. News to me, any way how do you tell them apart, I presume it was either a different head gasket or piston that lowered the cr.
Or whats the story? I always thought ALL aussie 2lt were the same.

Automatic cars had the low compression version.  Not sure what identifiers tell you on the motor itself though

From memory i thought there was a casting mark on the pinto block, posibly lc or hc.

Originally the auto engines were low comp and manual high.
 
The pistons are different.  Have a different pin height and are stamped 'LC' on the top.
 
There are various theories about blue and black rocker denoting hi/lo comp engines however I have not found this to be consistent.
 
Shaun