Big Brakes

Trying to make up my mind about a brake upgrade 280 or 304mm
If I go down the road of fitting the big brake (280mm) conversion that will still fit under my std 15" wheels will I need to get a 15" alloy spare as currently I have the steel wheel spare ie will the 280mm discs fit within the steel spare?

I think the steel spare wheel is a 14".

On most MG/Rovers one fits the steel spare to the smaller rear wheel and the rear alloy to the front, even if it is wider than the other front. You will only be going slowly as you have the undersized steel on the car.

Thanks Steve I'll pull it out and have a look, I suppose whilst there I could measure the wheel well and offset to compare it to an alloy.

Talkingcars I did not say but if I go to 304 front I will definitely go to 280 on the rears and may even go 280 all round, still reading and musing on this.
Quite a few people think the rear is underbraked because of the weight distribution anyway and I'm tending to that way of thinking.
I like most people was used to front engine vehicles and tyre pressures were higher at the front by a few PSI, when I got the TF and looked up the tyre pressures I originally thought it was a misprint! Obviously there is a lot of weight on the rear and I know weight transfer will cancel a lot of this out but still feel the rears should pull there weight a bit more.

I will add my car is not fitted with ABS which doesn't concern me but I think that means I have a brake bias valve yes? and would appreciate any feed back about 280's all round does it seem to over brake the rear? Has anybody changed the brake bias and lived to tell the tale.