"Peanut" ports are also known as "round-ports", and they've been around far longer than the " '90s ". They were available in the early-mid '70s if not before. Some round-port heads even had tiny valves--small-block sized. The ones I've seen with my own eyes had normal "oval port" valves--2.07 intakes, and 1.77 (?) exhausts.
Rectangular-port heads had 2.19 intakes, some had 1.88 exhausts.
The Vortec L29 heads have "large oval" port entrances, but then there's the ski-jump cast into the port near the valve guide; which dramatically cuts down airflow. Stock L29 heads supposedly have better power production than stock Gen 5 peanut- (round-) port heads, but some of that power gain is due to the smaller chamber/higher compression ratio.