uglysincebirth

I have a 69 Z28 engine that I had built for my C10 street rod project. When I turn the steering wheel while its idling the engine stalls on me so parking has been fun. I have a brand new saginaw pump and hoses installed to the factory C10 gearbox. I also installed a filter on the return side to collect any junk from the old gearbox. From what I've read, sometimes the relief valve sticks on these pumps and makes it do the same thing this is doing but I would be inclined to think this isn't the issue since it is brand new out of the box. Maybe it has something to do with the engine I had built. It has a .525 lift solid cam requiring a 3000 stall converter. It runs 11 inches of vacuum at idle which has given me problems with the power brakes so I've had to add a big canister to it. I currently have 3.5 power valve in the Holley 600 carb which is a little low for the vacuum this puts out so I will be ordering a 5.5 for it but I don't think thats the problem either. Has anyone else run into something like this before?