Yes, the aspen/volare distibutor is a very good start. I am using 2 of them, and I will share my experience. I can't relate to owning a 170, so others may have more specific info. I can't tell by the numbers, but based on your description and my experience, you have reasonably identified the unit.
My 1980 aspen has run 18.96 in the quarter mile with the factory dist set to factory spec. Full super six, Ported head, badly worn block with poor compression.
My 1985 truck is heavy and doesn't have an EGR. On flat ground, the engine really pulls good. Far better than the lean burn did.
When the motor is cold, it will lug going up hills unless I really stomp on it.
It is also very prone to ping when pulling a load or climbing hills.I believe that the 11 vacuum can is too much without an egr and on my heavy truck. I suggest you replace it (the vacuum can) with something less agressive and then don't be afraid to push 12-14 initial advance. The only other vacuum can that I could find new was a 6.5, and I have not had a chance to test it yet. I think it will be a good change.
You will notice that your carb will need completely re-adjusted due to the change in timing at idle. Don't expect to drop it in and drive without dialing it in for a few days to get your best economy back.
Finally, I recently built a distributor for a member of this board. I started with the same item as what you have. I was worried that later down the line, some mechanic would 'correct' the timing back to the factory spec. To avoid some problems, I rebuild it for 22* of mechanical advance and 8* of initial timing, with the 6.5 vacuum pod. This should offer an easier dial in from the factory spec, offer good performance, and still run reasonable if it is mistakenly retarded a few degrees by a misinformed mechanic.