The theory is that the swirling air would better ATOMIZE (mix) the fuel/air charges. It makes sense, if you think about it. The swirling air would allow more air molecules to be exposed to the fuel, therefore promoting better fuel/air mixture. Better FAM would of course promote the mentioned benefits. I would imagine the most benefit would go to the Carbs, then TBI, and lastly to the MPFI guys. What I gather from the lack of evidence is not that the setup doesnt work, but that the newer vehicles are already working at or beyond the help provided by the Tornado. I would imagine that older vehicles pre 80 something would indeed benefit from this thing. Clayton

The whole swirl idea is the principle jet engines work on. Several sets of blades rotate to swirl the air, which is directed by vanes located around the outside of the turbine casing. The result is more pressure (comparable to a supercharger, or turbocharger) and a whole lot of power. I don't know about the tornado thing, it sounds like a cheap way to attempt supercharging. Stick with a supercharger. "The question was: will 305 heads make more power on a 350. Answer yes they will make more power on a 350 than on a 305" This statement is too generic, and I can't agree with it other than to agree that the same volumetric efficiency applied to more cubes will make more power because of the extra cubes. If you were to state that 305 heads make decent power on a 350 I would agree, or that if you already have the 305 heads that it might be cheaper to polish & port them (doing the work yourself, not hiring it out) than to buy performance or aftermarket 350 heads I would agree. As for performance, I guarantee a set of Performer heads, L98s, LT4s, or several other 350 heads will outperform pretty much any set of 305 heads. The determining factors for what heads are needed or should be used depend on the application. In this case, 'spartyon' started this topic and is already running a 350 (per the signature), so I have put forward the question what heads are on it now? The second question I'd have to ask is what is your budget for heads or head work? And lastly, is this a daily driver, a strip car only, or both street and strip? Before stating that 305 heads are better on a 350, or even 350 heads are better than 305s we should have all the relevent facts available. What sense would it make if this guy already has a set of 350 heads to get rid of them to bolt on a set of 305 heads, and if he's running 9.5:1 compression and goes from 76cc to 58cc he's going to pick up 1.5-2 points of compression and end up 11-11.5:1 compression. At that compression, he will most likely have a set of cracked heads using iron (without one major polish job and cooling system). Obviously he could use a .060 head gasket and drop some of that to be more streetable, but I think the application and your personal budget should determine what heads you use. Smaller ports are more responsive to throttle changes as is a dual plane manifold, but both of these are only good for lower (5500) RPM ranges. Anyone planning to run 8000 or so should go with larger ports and a single plane manifold regardless. It all depends on your usage. Compression can be controlled through other factors, so heads can't really be judged by that aspect fairly. They should be judged by port volume, valve sizes, and flow results and per application. Personally, I will continue buy performance designed 350 heads for any 305s or 350s that I build, because I can.

[This message has been edited by jag (edited November 08, 2001).]

a lot of the circle guys use them because of the restrictive rules. 2 bbl carb, stock intakes, exhaust manifolds. Who cares about head flow if you cant get any air in or out.

Not taking sides but I have seen what Fbird88 has done and it is quite impressive . Check out what he has posted and what he has done with these 305 heads over the years. Like my grandma used to say " Son ,the proof is in the Pudding". Enuf said.

How about seperating those long, rambling replies into some paragraphs there, Jag?

Not only are your replies long winded, they are impossible to read with no spacing. It's like you are just trying to blurt out everything at once.