I was thinking about the factory testing procedure for stock mech pumps. I came to the question is a stock BB truck fuel pump capable of delivering a 10-12 second volume needed for WOT operation? Or is it barey handing on?
Milan

I would say it's marginal at best and I would definately upgrade to something like the carter mech street/strip or strip pump for your setup.

Scott

I must be the only one running 118.75 mph in the 1/4 with a hipo AC pump then. If it crpas out, I'll have to switch to the Carter 172.

Gene,the hipo AC f/pump is a good pump and your absoultly correct about it being able to handle a hot setup because your car is the proof it works.

The above post did not state that he was running a hipo f/pump of any kind so i assumed it was a std low perf 4-5 psi pump. Thats why i suggested the carter pump because it's a good pump i have used in the past. But if someone wanted to keep the stock appearand they could use the GM/AC hipo pump like youre using.

By the way,you know a lot about chevy's (Esp BBC) so would you happen to know what the pt # would be for an AC/DELCO f/pump that would put out approx 6-7 psi max for my 69/396 with a Q-Jet?
From what i understand the Q-Jets can only handle
6-7 psi max so an 8 psi pump like your running would be too much for my Q-Jet.

I am running a mild perf cam and i get the feeling at times it's running a little flat on the top end (in the 5200-5600 range)and think the stock 4-5 psi pump is marginal at best and could be the problem.

Some times it's hard to tell weather it's the cam thats dropping off the power band or the f/pump is on the edge of not keeping up with the fuel demand.

So i feel it's not that exspensive to try a f/pump with a couple more psi to see if the motor
will make power into higher rpms or if it does not help at all.

My prior cam was spec'd to 5800+ rpms which it would power right up to that rpm. Now i rblt the motor with a little milder cam that's spec'd
to 5600+ rpms but it seems to go flat at approx 5200-5300 rpms with the same carb,intake,exhaust,etc as i ran prior to the rbld. The only change was i replaced my hipo carter /pump with a stock GM/AC f/pump for a 396/325 hp to retain the stock appearance which is why i think that may be the weak link in my setup that's holding me back a little on the top end.

Scott

Jim Hand and others get good results with a Q-Jet by using lower fuel pressure and the high flow needle/seat, in case you haven't tried that.

Scott, I don't really know the P/N on my current pump. I looked up a 435HP/427 pump and its not it. That pump has a deep well on the bottom, this one isn't.

I wasn't kidding when I said I'd go to the Carter 172 when my pump claps out, I can't readily ID it. I wish I could, it's stock AC, pushes 9 psi at idle according to a cheapie guage and works mint. HOWEVER, it might be the case that I have 3 fuel bowls, so the volume in the bowls is sufficient to last for 12 seconds when I go WOT.

Here's the Q-Jet article I was talking about - it's about 14 pages. Jim Hand's comments are at the end. Check out the last two paragraphs.

http://www.geocities.com/gtopercy/Pictures/quadrajetTech.html

Yes, he uses an aftermarket fuel pump.

Glen/Gene,thanks for the info on the fuel pump and larger needle/seat for the Q-Jet along with the Q_jet article,it's much appreciated.

Scott