This might seem a little trivial, but I need a little advice on what I should do about draining the gas in my tank. Here's the situation: Old 305 out (86 LG4), new engine in. The catch is I have 87 in the tank and the new motor will need premium. Now I probably only have 5 gallons left in there (judging by the gauge, but we all know how those are) and I have started draining it slowly from the fuel pump on the block.
Here's where I need advice, should drain it until there is no more gas coming out, or should I leave some in? I'm thinking I should leave some in as not to uncover the pick-up and also risk dirt and other particles getting into the fuel line, although the car has very little miles and it was well taken care of so I doubt there is that much dirt in the tank. Secondly, I'll be getting some premium to fill the tank before starting the new engine, would 5 gallons or so be able to dilute the old gas as not to cause a problem? Thanks...

 

The real issue of having too little fuel in the tank is running the pump dry. They need fuel to keep cool.

Premium vs. regular is really only an issue under load conditions. 5 gals premium b/4 starting should be more than enough to get you through the initial adjustments and to the station for the first full tank of premium. Assuming you're going to do some break-in before WOT, it should be all premium when you need it.

 

Thanks for the reply Five7, it sounds like I should be fine. Yes, I will be doing the break-in procedure on the new engine before any WOT runs. I guess I was concerned if I accidentally drained the tank too much, but I'll just make sure I don't....

thanks...