My son has that setup on a 75 only he added Nox. If you push it hard, and why build it to over 500 hp if you are not going to, you need to upgrade the drivetrain from the flywheel back. It's that simple. I build these all the time. With my sons setup he broke a prepped 10 bolt diff, 2 super T10 4 speeds, twisted the drive shaft, broke the slip yoke on the new Tremic 5 spd, Dead hooked and sheared the inner/outer 1350 solid spicer joints. I ended up building his one of my 1480 12 bolts using Tom's axles, Tom's offset arms with 31 spline outer axles setup to my spec's, 3.5" 1/2 shafts, custom driveshaft with 1350 slip yoke and billet 1350 pinion yoke, frame gussets, solid mounts and a LOT of machine work and custom fitment. The most power I built a diff for was 950hp at the crank.
IF you are overseas, good luck with finding someone that knows these. There are very few here that know how to do it and I haven't seen anyone close to the way I built them. If you have access to a machine shop and take your time call Tom and get his 1480 setup and give it a shot.