Manster would be small to play DT today. Not in heart or desire but in stature. I don't think he ever weighed much over 260 pounds. Even OT and G were smaller back in the day though. Heck Rayfield Wright only weighed around 280 pounds
Manster would be a LB'er today and a damned good one. My favorite Manster story was when he drove through a picket line because the players were on strike and if players wanted their annuity they had to cross the line. He just wanted to play football, screw the rules and the money wasn't big back then. I think the story was he drove up in a big old truck with Don Smerik beside him, revved the engine, popped the clutch and the players had to let him through. It was ugly but that was Manster.