No. Leaf blowers blow air upwards of 120 MPH. Try a shop vac. Could they? Yes in theory, I know of shop vaccum's that can suck air even though they are only connected to 150PSI. Its all in the design. See link for example... http://www.gison.com.tw/product/P0000000149-Air-Vacuum-and-Blow-Kit.htm
Several things could cause the Ford vans rear air to not blow. There could be a blown fuse to the blower motor. The fan control could be bad, or the motor could be failing. Also there could be a wiring problem, or the hose from the blower to the vents could have a hole in it, diverting the air.
A blow through carburetor is one that has been modified to operate under boost pressure, from either a turbocharger or certain blowers. This would include seals on the throttle blade shafts, and boost referencing the power valve and float bowl.
There are several ways to blow up a cars engine. If your car loses all its oil and you don't shut off the engine you could blow it. You could blow it by over revving the engine for long periods of time. If the engine doesn't have water in it it could run hot and quit.