Nissan: 95 Nissan Sentra Engine?

I have a 1995 Nissan Sentra, but I think the engine has been replaced. I
have had slight problems before with parts fitting just right. I am in the
middle of replacing the timing chain set and have found out that one of the
new chains is a bit longer than the one I had, there wasn't a Valve Timing
Control cam sprocket in the set, the upper chain tensioner wasn't included,
and it looked like there were 2 of the same lower (right) chain guides. I
realize that it is possible that the kit is wrong from the factory, but
before I reorder and find out that the kit was correct, I want to know if
there is anyway to tell what year the motor is. I know it is a GA16 from the
engine block code. There was another set of alpha-numbers following the
"GA16" which were "972755Z." At the very bottom of the block there was a
larger "M2" stamped, and another set of alpha-numbers "4X28C." I have spent
several hours trying to find something on the net. From researching parts,
it seems that from 95 to 97 the engines are identical. It also seems that
from 91 to 94 the engines are identical. Can I assume that if I reorder and
the kit is correct that a kit for a 94 Nissan will work? Please help! If
there is anyway to tell the year motor I desperately need to know. Thanks in
advance!