Would 2 Holley 110 GPH fuel pumps with a 3/8" line support a 496 with a 260-268@.050 lunatidyne cam and 950HP carb? Or would I be better running a 1/2" line with a different pump?

You mean 2 3/8" lines? I was told by Mr Baird Mc71454 that he ran the carter 172 pump through the stock 3/8" lines into the low 11's and another guy who runs 10's in a stock unsumped tank with stock lines. IMO you should be ok. But the bigger line means less restriction and less work for the pumps

I just got off the phone with Steve Slavik at Lunati, and he informed me that 1/2 line from the tank to a T or Y, then 2 3/8's lines to the pumps and back into a 1/2" line would work well.
Opinions? :D

WHY 2 PUMPS??????

Thats what both Harold and Steve recommended... must not want fuel problems... He said that the Harold grinds require more fuel than average due to their inherent design... :(
So, 2 pumps it is. :D

All you need to do is keep the carb bowls full. Then it is up to the jets.

I just can't grasp the concept of a cam needing a very little more more fuel having that much of an effect on a fuel system UNLESS The fuel system was already on the Ragged Edge of Barely being able to keep the bowls full anyway. THEN if you install a Harold cam that uses just a few drops of fuel (which is a reasonable claim) I beleive you could starve for fuel.

But the fact that the Harold cam sends the fuel pressure down to 0 to barely 1 psi, is just a matter of having no performance safety factor built in your fuel system design and it should be improved no matter what cam you run Harold or not.

For Example:

Even running at 2 to 3 psi at the top end of the track I was able to maintain high 10.70's to 10.80's at 124 to 125 mph. in a test two weeks ago Running with an electric system that maintained a Rock Steady 6+ psi there was No Change in anything, ET or mph.

Use 1 Mallory 140 and the stock 3/8 line and be done with it. That is all you would need.

Scott B runs 10.80's with the 3/8 line and 1 Holley Blue.

Is Lunati just trying to overkill? :confused: I know you can get away with the 3/8's line, but wouldnt I just be riding the 'edge' shifting at 6700? And im going to install a NX or Nos system down the road (probably a 250 shot) :D wouldnt the 2 blues and 1/2 line would be sufficient? That way I wouldnt have to run a dedicated fuel delivery system just for the nitrous :confused:

Considering the possible NX, run -8 or -10 line, a Return Style Regulator with -8 or -10 return Line and a Mallory 250 pump. You won't be sorry.

Thanks for the advice graemlins/thumbsup.gif

-Jason