I think stock specs were around 250 hp and 325 lbs of torque.
You may be running just below 300 hp with those mods.
360's don't have very high compression so it is difficult to get much out of them.
I would get away from the double pumper. it would be overkill for it
If you go to rebuild it, I would throw a 390 crank/rods in there and wake it up.
I just did pretty much the same build with my 1970 Camper Special and it runs much nicer.
I ended up getting around 10 to 1 compression with a Crane 941 cam, Police interceptor manifold, Headers with dual 2 1/2 exhaust.
The motor works well like that.
I figure around 350 hp and 450 lbs of torque without puting it on a dyno.
Good luck with your project
Ken