Good Carb For Towing

[Polara Pat]

My dedicated tow vehicle for my 330 will be my '67 Polara wagon. I've done tons of towing with it in the past with varying results in fuel economy (heh heh) and power. Just wondering what some of you guys thought given my choices that I already have. It currently has an Edlebrock 650 avs on it. I also have a 600 (probably too small) and a Carter AFB (625 I think), I can also trade my buddy for his 750 Edlebrock. In Holley land I have lots of 3310s and I just got a core 750 spread bore vac sec that is sort of like a Q-jet. I thought this last one seemed interesting. Any other towing suggestions are welcome as well.

Oh, the motor is a .030 440 with flat tops, massaged heads and a serious tow truck cam. Edlebrock performer intake.

 

[Satellite65]

I'll bet with that 750 spreadbore and one of those 3310's you got laying around you could build yourself one helluva 'Frankencarb'!!! Go for it, probably work great.

 

[Polara Pat]

I'll bet with that 750 spreadbore and one of those 3310's you got laying around you could build yourself one helluva 'Frankencarb'!!! Go for it, probably work great.

Sort of what I was thinking but I'd like to hear from all the "super tuners".

 

[Meep-Meep]

I'm guessing your engine will spend most of it's life under 4500 RPM and the high end will be dropping to second pulling a hill. The overall size of the carb should take displacement and RPM into account, so my gut feeling is around 600 CFM will be fine - or that AVS. Also you have a heavy car and will tow another car so going down the road like a freight train I wouldn't concern myself with a lot of CFM. Keeping the proper amount of velocity is always important so you can't go too small or too big. I like Carters or Eddy's because they seem to have a nice primary circuit. If you get a stock replacement Holley it will probably be fine too but I wouldn't use that 3310. Those performance carbs tend to have great WOT efficiency but the intermediate range tends to be not as crisp. Have you considered a TQ? I know those are 750-800 CFM but that's only with the air door fully open.

 

[Polara Pat]

I actually have a ThermoQuad as well, I think it's an 800. I didn't include that in the list since I'm not really familiar with them. I run 3.91 gears so rpm is usually kept under 5000rpm.

 

[Meep-Meep]

Have you done a cranking compression check? Hopefully you have 150-160 PSI. That should make a nice driver on reg gas.

 

[Coronet 500]

I like the Franken carb idea.Holley vacum spring kits can really dial it in for your towing needs,don't forget to match your power valve to your vacum.

 

[Satellite65]

I actually have a ThermoQuad as well, I think it's an 800. I didn't include that in the list since I'm not really familiar with them. I run 3.91 gears so rpm is usually kept under 5000rpm.

That'll work well too, as long as the underhood temps stay under control. They don't like a lot of heat. The ThermQuad is actually a great carb and pretty easy to deal with.