My 1"x1" heater FINALLY showed up(partly my fault), and it looks like I could have gone bigger. The heater is only 10 watts, so I didn't expect much, but it does in fact work, and I did measure higher oil pan temps. I'll have to leave it plugged in for 2 hours and see what kind of oil temps it gets up to. I had it on for maybe half an hour, and saw oil pan temps climb about 6 degrees F. Temperature on the heater itself didn't go much over 200 degrees F.
Vacuum gauge is hooked up and sourcing vacuum from cylinders 1 and 4. Haven't gotten to ride it since that first test ride with 1 cylinder tapped cause I was fixing a coolant leak. The leak is fixed now, I just have to go get more coolant!