You should be fitting a beam well before changing the diff. Not much point in fitting a strong diff if you aint got any grip. IMO the Jaguar 10" is the solution & if its Power Loc the grip obtained is incredible. Cost. beam fitted with diff & shafts was £1700 & the diff cost £20 + a £400 overall. Does the prop need changes with the Supra diff. The standard shafts will twist like coke cans with big power.