Nope. The good tyres go on the front to prevent understeer1. Oversteer2 is preferable by far. IMO, It's easier to detect and a hell of a lot easier to control.
Well, it was wrong then, and it's still wrong now.
I wouldn't be too sure about that. I just ditched 4 good tyres in favour of 4 new RE720s. The rears were el-concrete-o brand. I swear they had not worn a millimetre since I got the car. Absolute pooe in the wet. The fronts were a pair of NCT5s that I was advised to try. Absolute pooe in the dry. So, they all had to go and the car is now much happier.
So replace them. That is no reason at all to keep the worse tyres on the wheels that control direction and do most of the braking. Just because the tread is legal doesn't mean they're any good.
1 This is when you go into the wall forwards. 2 This is when you go into the wall backwards.
-- Mark Foster, Brighton, Suslove, UK PGP Fingerprint: 3342 C02C 7BE8 3FE4 AAC5 8BB2 03B7 9263 DDF2 04C1 -------------------------------------------------- "There are no such useless words as...'I didn't have a chance.'" Driving, HMSO