If you're using a conversion, especially if it's an older (80's) frame, then the top tube could be shorter than more modern bikes with equivalent seat-tube lengths. This could mean that the bike is still 'small' for you. I had this problem with an old Schwinn. I also was pressing my forearms against the top of the bars when in the drops.

I changed to bullhorns. Not as many hand positions, but it works for me.