We have installed our LQ4 6.0L into our 77 Nova. Just fired it up today, and car is still up on jacks. The pump is from the 2001 2500 chevy truck, and we replaced the pulley to clear the steering box, so it now has a smaller pulley and is turning faster (about 1" smaller diam.). We've run the engine about 5 mins total, off and on, and each time hear a slight noise from the PS pump, and when we check, fluid is full of air bubbles. We've moved the steering lock to lock a number of times with engine running and not, and still getting foaming...wondering if it could be sucking air somewhere/somehow or cause....no leaks, all new lines, and gear box was flushed out as well as PS unit. Thanks, Chuck.