I don't think '92 is a watershed year. In late 94 or 95, the final iteration of the B230FT got the piston oilers and that version might be the ultimate Volvo 4 cylinder engine. Go to Turbobricks.org and look for the commentary by Mike Aaro who runs a Volvo performance engineering place in northern Sweden. The blocks are not exactly plentiful yet, but second place might go to the 90 and newer post-K blocks you are referring to. I think if yours was made in late 89 it might be post K or do you have a K sticker on the timing belt cover? I think the first K's appeared in '88 (late 87 manufacture).