• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

4bbl as fast as a Six Pack?

I have the original motor trend mag that highlights the 68 GTX on the cover. Believe it or not the article qualifies the 440 4 bbl as being faster on the strip than the 426 Hemi. No b.s. I don't want to rewrite the article on here, I'm too lazy. But take my word for it that's how history has it chronicled back in the day.

i switched mine from a 4 bbl to a six pack and can say it was faster as a six pack, but that's just mine.
 
I have my own opinions about the difference between a 6BBL & 4BBL....when you mash the GO pedal running a 6BBL, you CAN see the gas needle moving :3gears::3gears::3gears::rofl:
 
Some of the dyno test I saw had the six pack making almost as much hp as that eng did with the Victor intake and a 1000 hp carb. The six pack can make good power if set up right. The good single plane and carb is not always better then the six pack. Ron
 
mine seemed to be working pretty good when she went 11.69 spinning a few weeks ago on my pump gas 440 :yes:

july2013078_zps712ccc3a.jpg
 
I have a 6 pack on my 70 Road Runner and I can say from personal experience that YES the car does pull and run hard and YES it is hard to keep one's foot out of it and YES it does guzzle some gas!!!

But for sheer visual appeal, nothing beats a six pack or a multi carbed Hemi (especially at a show). EVERYBODY loves them!!

Its truly an expensive set up, but if one can afford it, its the way to go!!

There is also a good article on rebuilding and tuning a 6 pack in the JUNE (2014) issue of HOT ROD.
 
But for sheer visual appeal, nothing beats a six pack or a multi carbed Hemi (especially at a show). EVERYBODY loves them!!


Ah you forgot about this for awesome visual effect ! Ron

407388607.gif
 
The six pack will be very crisp on a street motor for sure. Actually better than a big four barrel. I would use a 950 Holley as an example for a mild race set up. For the street lewtot said their is lots of misinformation and he is right on. A Street driver with progressive linkage or vacuum will run really clean for low to moderate speeds, yes they look very cool, but modern single planes with a 950 really will make lots of mid to hi end power!
 
The only time a 4bbl beats the 6bbl is when there's two of them! I switched way back in the day on an essentially stock 440. The six pack was king. Since I still own the same car 40 years later - it's just been refreshed - and is still king!
 
update: i went 11.58 @ 116 spinning 1.70 60ft with my six pack that doesn't work. and i think the convertor is junk to boot. have to wait till next year to see what it can do.

photo2_zps275c0cbd.jpg
 
Just for some fun info. Different days, both decent weather. 2 full runs with six pack. 3 full runs with 4 barrel. This is on a 4000# (with me) street car. No other changes. Drove both setups to the track.

Six pack 500cfm center
IMG_2377.JPG

IMG_2378.JPG

IMG_2379.JPG


1050an carb, tm6, 1" open spacer
IMG_2429.JPG

IMG_2549.JPG

IMG_2532.JPG

IMG_2531.JPG
 
My 69 RR ran a best of 13.30 at 5600 feet. I was using an Eddy Perf RPM intake and a 780 carb. 100 MPH. It has ported 906 heads and headers. I bolted on a new six pack and carbs, that dropped it to 12.90@105 MPH! Didn't change anything else. Used the carbs just as they came, out of the box. No tuning or jet changes. One needle and seat on the rear carb was leaking, so I changed that. That's all. So that was .4 sec quicker and 5 MPH higher top speed at end of 1/4 mile. In my case the six pack wins.
 
The thing about the six pack set up, is that it increases torque throughout the power band. The torque curve is very flat, but way up there on the scale. You can see that in some of the posts other members have made documenting their dyno runs.
 
I also had a 69 RR 451 with a similar engine and trans set up, except it had an 850 dbl pumper on a street dominator intake, and 13 to 1 C/Ratio with Headers. I Used the 509 cam. That car would beat the 6 pack every time. It ran 12.40 at 110 MPH. The C/Ratio was the big difference there.
 
Last Spring I took my 496" wedge with a 6-bbl in my '69 Road Runner to Maple Grove. I had issues with my 6-bbl, so I also brought along a TM7 with an 850 Holley that was "set up" before hand. I ended up putting the 4bbl on the car and it ran an 11.62 @116MPH. This past black Friday, in better air at Atco (usually a tenth or two faster than Maple Grove) I ran my 6-bbl set up. It went 11.55 @ 118 MPH. I think the two are virtually identical in performance. There's no question which looks better, and I'll continue to run the 6-bbl. As a side note, I can definitely tell the difference in gas mileage between the two. The 6-bbl gets way better mileage than the 850. My two cents....
 
Slightly off topic but if anyone is interested that engine masters show on YouTube compared a dual quad set up to a six pack. Everyone agreed six pack looks cooler but dual quad way out performs. Would be a cool follow up episode to compare a big 4bbl to the six pack like we've been discussing.
 
Auto Transport Service
Back
Top