Whats wrong no oil pressure when pre-oiling 400?

Well I thought my drill was pretty good for what I paid for it. It's served me good for 2 years but I don't know if I had the switch reversed. Because when I had it in the position I thought was counterclockwise you could hear the gurgling inside the engine and the drill would spin really easily with no resistance at all even up to 3,000 RPM, the limit of the drill. Well I thought maybe I was confused and had it going clockwise so I switched it and attempted to run the drill and it about broke the drill. It's tight going this way, it will spin one quick time and the gauge will jump up to 75PSI and then the drill will quit and it goes back down. So it registered something on the gauge switching the direction of the drill. But it wasn't a steady reading because I couldn't get the drill to turn freely because it was too weak. Is there suppose to be some resistance turning the oil pump driveshaft with the drill? It's just a cheap 3/8" drill. Does it sound like I just had the drill switch going clockwise instead of counterclockwise and that my drill is too weak? I would assume so, since it immediately got a reading on the gauge whereas turning it the other way was a breeze and registered absolutely nothing on the gauge.

Yes you must have had the drill going clockwise instead of the correct counter-clockwise rotation. I also have a melling HV pump in my 440 and when I primed it my drill slowed right down and oil psi shot right up. My drill could barely keep spinning and started smoking. Even with the drill barely spinning the gauge read lots of pressure. Now that the motor's back together and the car's driving it's got lots of oil pressure, works great, although to be safe with the higher capacity pump I did do a 7 quart pan/pickup.

I guess I'll have to go get a 1/2 drill or borrow one. I know I shouldve gotten a stock oil pump or a high volume but it's what we had in stock. I'm building this 400-4bbl stock. It's already been bored .040 over, there wasn't a ridge just needed a honing, 3-angle valve job on stock heads, Speed Pro/Sealed Power Cam, Sealed Power bearings, Hastings Cast rings, Elgin springs, MP windage tray, 73 HP exhaust manifolds, 73 iron 4bbl intake, remanufactured Carter Thermoquad, and 73 4bbl air cleaner. So it's about as stock as you can get. Hopefully it will just be a good cruising car. I've got a stock rebuilt 1975 727, 8.75 with 3.91 posi, front/rear sway bars, Accurate dual exhaust, and the coolest thing a Standard gauge cluster from a 72 Highway Patrol Coronet reading "Certified Speedometer". I did want to add a tee and plug in a mechanical oil pressure gauge as well as my original oil light. I has a bad experience with my oil pump giving up on a winter road trip in Kentucky in my daily driver Ranger but it did have 228,000 miles but no warning and no changing that oil pump on the side of the road. Any articles on how to do a dual oil pressure gauge/light hookup anywhere?

Somebody above was correct. You need to spin the drill the other way.

big block is counter clockwise..

Sounds like there is no problem, as he said he reversed the drill, the gauge shot way up and drill stopped. Maybe the drill is just too weak, and was being turned the wrong way initially.