Vacuum with the new head / other first impressions

Keep in mind, the Autolite 480cfm 80Stang is using, is quite a bit different than the Autolite 480cfm Speadbore. Therefore the results could vary considerably. Its like comparing apples to oranges.

A stock Autolite 480cfm has 1.08 primaries, and 1.08 secondaries. Pony Carb's 480cfm Speadbore is actually a 600cfm carb, which is custom fitted with 1.00 primaries, while maintaining the stock 1.12 secondaries.

As we stated in our test results, the size of the primaries seems to have a dramatic effect on the performance. When we installed a carb, 2V or 4V, with primaries larger than 1.02, we lost power......

I think carb selection is more like a turkey shoot than anything else. Ya just have to go with what works best for your specific engine build. 80Stang's seems to like the Holley 390, Geezer's likes the Holley 600, MikeR's obviously did better with the 480 Speadbore, while other members have had good success with a Edlebrock 600 and a Holley 500. Is there such a thing as the perfect carb? Who knows? Obviously, it's going to take a lot more testing. Right now, we have the results from six different builds, and they all have a different carb. ;)
 
Okay, 400 miles up here and the car got all the way in one piece.

For what comes to carbs the Autolite I tested was a normal 480cfm but I recall the venturis are 1.06 or then I have studied the numbers all wrong. Nevertheless, it might have worked way better with more tuning but "out-of-the-box", meaning in this case thorougly cleaned and with all new gaskets etc, it did work decently on my engine for what comes to idle quality and useability, but performancewise it did't pull nearly as hard as the Holleys do. I had to alter jetting to suit better, and at WOT I was in stoich A/F although some richer than with the Holley setup. During the past years I've noticed the tweaked L6 seem to take time for carb tuning but it is very teaching, and I can believe all setups won't work with same solutions. I happen to own a bunch of carbs, and I could still test Autolite 287, 300, 351cfm-2V, Holley 350 & 500cfm-2V if I only had some time to do it, but right now I'll stick with what seems to work best for this engine.

What ever the carb, the key to some respectable power is the new alum head, which is about as good as it can be for this small-bore engine.

I'll be on dyno within just a few weeks from now on so then we'll see how it really performs. Before that I can just present some pics and video as soon as I get something I can publish.
 
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