High Idle with pulsing when on brakes
 

OK guys, so I haven't done anything to the motor yet besides removal of unnecessary items, ps, a/c, charcoal can, etc. I just dropped in a new motor, wired everything back up, and it starts up fine. Idles high at beginning start up probly because of warm up, then usually will make it back down to 900 idle. When I apply the clutch it will sometimes jump to around 1100, but when applying brakes it jumps to about 1700 then drops to 1400 then jumps and drops, does it 3 times and then will stay at around 1500 with my foot still on the brake. Letting go of the brake doesn't drop idle. Could it have something to do with the BMC, checked all electrical and everything looks right. Timing isn't the issue. Could it also have something to do with removing all the accessories and motor not having as much load on it?