...and I should also add that Park's best contest weights were probably in the 218-222 lbs range ...probably in the 8-10% body fat zone. Considering that Reeves was 213-215 onstage, at a similar body fat percentage but with a smaller build, there really isn't much cause to think that Park must have been on steroids. That isn't to say that he didn't necessarily try them when they would have become available to him, likely in the 1960's, but there's nothing in the numbers that screams drug-use.
Schwarzenegger, however, is not as thickly built as Park was, yet outweighed him by 10-25 lbs (hard to know for sure). That makes me think Schwarzenegger probably would have been just larger than Reeves had he stayed "clean".