if youve got the a14 already, just grab some extractors and eother a webber or twin carbs for a bit of extra power on the cheap. depending on the soundness of your engine,with the new set up you could advance the timing for 98 octane fuel for maybe 5-10% more power depending if your car is stock or not engine wise.
It all depends on whats in there already and your $$$$ situation.
Did you get your back end fixed yet?