i was less than satisfied when i had the same sorta brakes on my car many years ago. you know, back when i used to have a 1200 that was on the road
mine was the landcruiser calipers some kinda camry vented discs and standard r31 rear brakes

possibly because they werent set up 100% perfectly
possibly because im picky with brakes
possibly because the next brakes they got compared to were full size r32 items(which were awesome)
but i just didnt like them

R-fast runs cruiser calipers and silvia(i think) discs on his race car and they are apparently pretty good, and also fit under 13s...once again beaten to the big brakes



But i think landcrusier calipers and what ever disc and r31 rear brakes are the text book big bolt-on* brakes to use under 13 inch mags

*note, brakes arent actually bolt on