Dan, it does a bunch of stuff...you can hook it up to your plug wires and cut individual cylinders, or check the performance of each cylinder, do all your dwell/timing stuff, tests your exhaust output, does leak down tests, tests all your ignition components, and lots of other jazz...it really is a PERFECT tuning aid for the old stuff. It's a cool, cool piece, and last time I fired it up it worked...but as I said in the ad, I have another one of these will lots of extra goodies (including the lower cabinet spec sheets), so there's no need to have an extra in the way...but it would look KILLER in your garage!
Verne: this model 400 would dwarf that model 900 of yours! But those are cool machines in their own right, and *definitely* worth hanging onto!
