Aluminum is far stiffer and doesn't flex. All reels were 4000 size. Yes it was a lot of strain pulling 5 lb bass out of thick weedbeds in the summer. Don't member model numbers was over 30 years ago.Use all baitcasters now. Baitcasters have progressed to the point where you can use them for really light lures.
Never had issues with aluminum spinning or magnesium reels. If your fishing musky get a 4000.i listened to kvd who doesn't use small spinners.he says it's not worth the line issues. Less issues with bigger spool on a spinning reel especially with flouro. Pflueger makes a spinning reel for 99 with magnesium frame. Used mine for years then gave it to my daughter who is still using it.i personally prefer Lews reels