VIN #

I have 66 chev carprice,VIN# 1666396S128929. About in 1987 it had another long block installed,with block eng# L 6 230810 TO62IIN . Can anyone tell me the yr. of this 396 and also the hp. I've been told there are two different hp on this eng. Thanks a million----Bruce snipped-for-privacy@msn.com