O.G. speed shop on O.G. road have installed a crane ignition system into a AE71 4AC, the change was massive, better fuel economy,more power, starts 1st go and never having to adjust points again i think the cost at the time was 280 fitted which is pretty good considering it was fitted.
I'm over adjusting points ill be getting one soon myself just to increase the reliablity of my already pretty reliable AE71.
http://www.cranecams.com/pdf/90002000a.pdf might have a go fitting it myself.
http://www.ogspeedshop.com.au/ give em call check out the site