I have a '72 142s that has a tired motor. I chose a '74 B20E motor, the injected motors here in Aus come with 10.5:1 compression, bigger valves, bigger ports and a few other things. I'm using the original twin carbs to keep it looking like a B20B, it should have considerably more power than the original B20B. Others have got heaps of horsepower out of these motors, I would too if I had the money. The B20E comes with the same crankshaft as the B21 so it has an 8 bold flywheel instead of 6, so you wont be able to use the B18 flywheel. I intend to use a B21 flywheel to solve the problem, I hope it fits. I love the 142s model, keep us posted, I would be interested... Matt