The reason we went with the fuel pump that is on now is all the others said they were only for 2bbl carbs.
That's because only the 2bbl carb'd cars came equipped without vapor return lines. But that has nothing to do with fuel flow capacity, or what type of carb or engine the fuel pump supports.
Basically saying Carter's regular 'ol stock replacement pumps will deliver enough fuel to satisfy most engines up to 450 hp. They all flow the same amount, with or without the 3rd port. And if you need one that delivers more fuel than the standard, they offer a competition series M6907, and it does NOT have a vapor diverter port. It just flows 3x more fuel to supply high HP/modified engines. Check out their part number chart at the end of the article.
As long as everyone else has drifted off topic, I might as well toss my 2 cents in:
Haven't purchased pure gasoline in nearly 20 years...it's simply not available in Indiana at the pump unless you're buying race gas. If it's for sale at a certain station somewhere I have NO idea where that is. So E-10 is all we get here, period. On the old cars I do occasionally replace a vintage brittle or cracked rubber part with a more modern alternative material, and I have retuned/rejetted some of my old stuff to get them to run at peak. That's all. It does NOT hurt steel tanks or lines. It DOES eat up some fiberglass tanks...big problems on some really old boats. It DOES eat up pre-1985-ish rubber fuel lines, which are 30+ years old now and LONNNNGGG overdue for replacement anyway, so I say so what?? It does not eat up modern ethanol-resistant, lined rubber fuel injection line, which is a stellar replacement for plain rubber, and looks like plain black rubber on the outside. It might hurt some carb floats, depending on material, and accellerator pumps and maybe a float bowl gasket. Again...if these parts are older than 1985-ish and they fail now in 2012, how can someone blame ethanol mix over normal aging for their failure? If those parts are post 1985-ish, you're pretty much good to go.
But I will say I personally have had no fuel related problems with E-10...boats, mowers, vintage cars, vintage tractors, new and vintage snowmobiles, motorcycles, 2 stroke injected and/or premix, etc. 20-ish years running.
I like Startron additive, they say it allows storage of E-10 up to a year...I put it in my boat/mowers/Fbird/etc for winter storage, and my snowmobiles for the summer storage. I have actually stored it up to 2 years and it burned it off perfectly fine with no ill effects: http://mystarbrite.com/startron/
Frankly I LIKE the fact that it keeps water in suspension and burns it off during use, unlike pure gasoline which will allow water to puddle at the bottom of the tank...particularly on snowmobiles...no more frozen gas lines, and no need for adding Heet to prevent it! So you won't catch me complaining about E-10.
I've never experienced phase separation.
I've found that with a few easy and minor maintenance mods and knowledgeable tuning, it works perfectly fine in everything...68 Firebird included. Just had to replace some rubbers and throw the factory jetting/timing specs in the trash and tune it for whatever fuel you want to run, that's about it.
