I've installed the Petronix(?) Ignitor on 2 cars and have seen the Crane setup on a few cars. The Crane is well rated and everyone I know that has used it was very happy with it, no problems and it seems to work in any car. The drawback to the crane is installation time, the higher price and the fact that it doesn't appear stock (modern black box & wires bolted to your firewall). The ignitor (petronix?) is easy to install, less expensive and hidden completely inside the stock distributor & cap. The disadvantage of the ignitor is that it doesn't work on every distributor (you have to check the P/N closely, many Volvo distributors are incompatible) and probably isn't as high quality as the crane (keep a set of points with you as a backup).

My advise: If you don't mind spending a few hours installing it, the unstock appearence & can afford the higher price, I'd go with the Crane. Otherwise take a chance on the Petronix for about $70, which might work out just fine.
--
Tommy '64 122S