In the comments section for this onboard video there's a little conjecture over the actual driver for this Porsche 956. But regardless of whether it is Stefan Bellof or not, it's 10 minutes of the most absorbing onboard footage you will find.
Every corner, every straight, every lap passes quicker than expected. At the old Bus Stop chicane and La Source the cars seem almost stationary compared with the outrageous velocities they're achieveing at Blanchimont and down Kemmel. Revs flare on downchanges and the whole car's attitude seems angry; it requires real effort to drive very fast. See also from 7:25 for some heroic opposite lock out of Bus Stop.
Um, and that's about it really. A 956, Spa, and one rather talented driver.