IMO using a torque converter isn't the best idea because when it's not installed on a trans. the insides are left to flop around which will throw the engine out of balance. You'd be a lot better off finding a flywheel to use for that task. Plus a bellhousing makes an easy mounting surface to bolt to your engine run stand. You can usually pick up a 11" truck bell and flywheel fairly cheap. I found a set at a swap meet for $50 that I use on my stand.
