Dwell at TDC?

Well, there's increasing the likelihood, and makign it detonate. I dont think simply changing the stroke will make it ping. But it might make it more likely. So that means you be more careful with tuning and parts prep. Most bad things that one can do to an engine have things that can offset that "bad". Like running quench in a wedge engine with a closed chamber head. Or runnign aluminum heads to help reduce the tendency. For what you propose very little is changing. You are running a longer rod. Not "stroking" the engine. I'd make sure the pistons are decent quality and dress the sharp edges. Have the heads' chambers cc'd and smoothed out. Run a cam that doesnt build a ton of cylinder pressure (no higher than a measured185psi) and pay attention to how to set up ignition curves and carburetors. You should be fine at a true 10.5:1 with attention to detail.