What is the weight of a 1988 Mustang GT hatchback with 5 spd. manual with most options other than the T-top?Put the wheels and tires from the 88GT on the 12' Boss 302 (if they would fit) and you would see a HUGE gain (not loss) in stopping distance. Modern tires are night and day better than what was available in '88. Also the 88 GT weight is LESS than a 12' Boss 302. So tire technology, tire size, ABS and chassis advancements have allowed a heavier car to stop in a much shorter distance.
I would think that the Boss 2012 model braking would not be as good with the 1988 tires compared to the 2012 model because as previously mentioned the improvement in tires since 1988 and the fact the 2012 has Brembo brakes and are larger in size than 1988.
The 88 was fast in its day and a lot more simple of a car compared to the new Boss which I like also. I would expect a big diffeence in braking as the brakes in the 1988 5.0 are inadequate even back then.
The 1988 is alot easier to work on yourself. Distributor, cap, rotor so easy to remove and replace. Spark plugs not bad to replace, fuel filter..maintenance is very simple.