tell me what kind of carburetor should I buy

Dave, I've got a Holley 750 DP, I took it apart and cleaned it up, however the gasket kit I put in it wasn't Holley brand, so the rear bowl leaks. If you want it you can have it for $100, it's the newer style with the plastic pieces. I'm in BC so shipping would be cheap.
You just need to take the bowls off and use Holley gaskets.