I have a holley blue pump that I thank is going bad ! what would be better re build the holley or take it out and put in a " bd pump " and hook it in to a oil presser switch then hook up the factory pump? thanks

 

Well, first off, is the 'factory" pump you mentioned a in-tank dealer fix job, or is the the original pump mounted on the left side of the block?

 

left side of block

 

In that case I'd dump it. The BD kit is OK. But remember, it's still the same type of pump as the stock one. And the Holey Blue is good; but there are people you have had good luck and some who have had bad luck using them. If yours went out, I don't think I'd trust a rebuild. You'd be looking at the problems down the road. If you have the extra funds, make a good investment in something really good. On the low end of good pump systems, look at Raptor 100. It's priced really well and it's super reliable. It also comes with the 1/2" fuel lines to go from the tank to the filter and all of the fitting you need. At the top end you can look at an AirDog or a FASS, but now you're talking some money.

No matter what you do though, get that pump mounted down on the frame. remember, electric fuel pumps work best as a pusher, not a sucker.