Posted by Ken in CO on Thursday, December 28, 2000 at 10:47AM :
In Reply to: Re: 6 Pack on a 1978 Power Wagon posted by R Davis on Thursday, December 28, 2000 at 7:47AM :
Well, no specific experience with those carbs, but one thing to remember with BIG carbs, generally your low airspeed(ie low rpm) performance will suffer. As the venturies get bigger, the smaller the vacuum 'signal' at lower rpm and thus less efficient atomization and less precise metering. Are those a progressive system? I've had specific experience with this using the 350 and 500 cfm Holleys on a smaller V8. The problem with a 500 cfm 2bbl is that it would be a 1000(or more) cfm 4bbl. That's a lot of carb. A 440 can certainly use it, but where in the rpm range? Not below 3000 rpm. Those 440 six packs perform quite well in the muscle cars, PROBABLY(not absloutely) not the best setup for a truck, excepting a mudder. Perhaps a sixpack of 350s running progressively? And don't forget that hoisting a six pack onto an otherwise stock truck 440 is a waste of time and money(excepting 'cool' factor), you need the whole package: heads, cam, exhaust, ignition, etc. for it to perform on top.
Finally, from performance engine design classes years ago, all those older multiple carb setups can be outperformed using modern single carbs on a good manifold. The carb technology did continue to get better, even through today with injection taking over.
If you're into 'cool', the six pack definitely is.
I must say that with further thought, the 350 carbed six pack running progressively could really be a good setup for a truck, you get small carb performance on the low end, alot more carb on the top. Are the six pack manifolds a 180 or 360 design? Hmmmm...
Ken
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