Older 5.0's had the 2-peice, and the newer ones went 1-peice. I beleive the 1-piece will retroactively swap into older cars though...not sure.
If we knew the year of the 302 in question, we could give a better answer. If it's a '87 or later, definitely 1-peice. Not sure when the swap to the 1 peice happened, but i wanna say early. 1984ish?