Personaly,I wouldnt do it.I think your 99 is probably worth more.Dont you already have a turbo charged racecar?Why have two racecars?
The 89 just doesnt do it for me looks wise.I love fox coupes just not that one.What kind of power is it making?No aluminum heads.I would say the 89 is only worth maybe 7grand.Surely you can pull more out of the 99.
In the end its up to what you want though.Which do you like better?