Hot air of stove into which plenum of oil furnace?

Thanks for all the replies and pictures. I ended up staying out of the plenum after reviewing WNY's recommendations. I will post some pictures shortly, but here's a summary of what I did:
8" Stovepipe off the top of the Keystoker output into an 8" galvanized Tee just below my floor joists. In one direction, I plan to put an short 8" run which is presently blocked off, into the wall above the man door enterance from my garage so I can push heat into my garage (when needed). In the other direction, I reduced down to 6" (galvanized) and have a 15' run that Tee's into an existing run from my propane furnace. From the same 15' run I place another Tee and jumped into a joist cavity where I've run some oval stack (another 15') to get above my wiring and jumped back down below (converting back to 6" galvanized) the joist to Tee into 2 additional existing runs from my propane furnace. Using a series of manual dampers to close off the furnace runs and to balance the system, I've now got a perfectly balanced system pressurized by the 500CFM fan on my keystoker. I have a 2200+ sqft Colonial - now heating completely with the Keystoker, two runs on the first story and one run on the second story - all with great volume of warm air output. My first story is currently 70* during the day and second story hangs around 68-69*, plus our hardwoods on the first story are about 15* warmer than before there was any heat to the basement radiating from the Keystoker. I let it kick down a few degrees at night, and we leave the bedroom doors (all on the second story) open to allow the heat to flow into the rooms. My propane furnace is still there to supply some quick heat on cold mornings and to humidify the air when the humidistat calls for moisture. The only down side of me avoiding the furnace all together is now I'm not filtering the air that's pulling from the basement floor. I'm looking to have a sheetmetal fab shop build me a triangular filter box to nestle behind my Keystoker (it's in a corner) with the filter faced outward to the rear of the stove. I'll attach a 6" round takeoff to my intake of the 500CFM fan and use an adjustable elbow or two to tap into the custom filterbox. Any other suggestions to filtering the air would be welcomed~

I promise - pictures are coming once I fix my idle problem discussed in another post: Help! Keystoker 90 DV - Keeps going out at Idle

Since my hot air plenum is located closer to my stove than the cold air return plenum, & since my central heat never is used, I have some warm air drawn from above the stove & blown (bathroom exhaust fan in the FR ceiling) into the hot air plenum to trickle out of the floor vents upstairs. Works fine as an additional source of warm air upstairs.

Great!! Glad you figured it out and it's working.