When your rear brakes get to be too powerful,
and they lock up the rears before the fronts do;
then you are just micro-seconds from spinning out.
This really sucks in traffic.
Which isn't a problem with 10x2.5" brakes if you use the matching 73+ BBP disks. Or the 11x2.5" drums with the later 11.75" B/R body disks. Both of those combo's are better matched than anything that the SBP cars came with IMO.
And honestly, if you're really bothered by that possibility, you should plumb in an adjustable prop valve so you can dial the brake bias in to match your car. Because once you start doing things like staggering the tire widths front to rear, changing the suspension or moving things around that will change the weight bias front/rear or move the CG the factory valve won't be as accurate as it should be anyway. All of those things can change the required front/rear brake bias, and many of those things are pretty common to do on these cars. Especially the tire stagger.
What you shouldn't do is just run around with little bitty rear brakes because you're worried about making the brakes "too powerful". Most guys run wider tires on the back of their cars than they do on the front, which makes them harder to lock up. Which means that more powerful rear brakes can be pretty helpful as long as you do it right.
