Have any of you tried these

[CobraEd]

I am hearing good things about the tapered 4 hole carb spacers. There are about 4 people who make them. Seem to add 10 - 15 hp. Any of you have any first hand experience? Here are two.

http://www.jomarperformance.com/powercone.php

http://www.highvelocityheads.com/ss.htm


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[DAVID GAGNARD]

Mine is a custom made piece made for a dyno shop to test, it added 16hp and about the same on the torque side on my 331 stroker.........

It's a little different from the ones you posted about as it was an expiremental piece. It is probably close to 10 years old now.... The only difference I see is the taper, mine doesn't taper out as quickly and turn to an open spacer.. the "bells" have a more gradual taper to them......but it works.......dyno tested on my motor.......

Edit: I looked over the info on the 2 sites you posted and 40 to 47hp "may" be possible, but I'd have to see that to believe it....

I helped out in a 2 day dyno test of a 600+hp dirt late model engine. One day was dedicated to testing 2 very different carbs and a total of 6 spacers, one each in wood and one each in aluminum. They were an open spacer,four hole spacer and the "bell/tapered" spacer. The results we saw were that no spacer made more than 23hp over no spacer at all. One carb actually did better with the 4 hole spacer than the tapered spacer!!!!!!!!!!!!!

David

[ERA Chas]

Originally Posted by CobraEd

Any of you have any first hand experience? Here are two.

http://www.jomarperformance.com/powercone.php

http://www.highvelocityheads.com/ss.htm


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You need all the info. As a general rule these work best (12-18HP on Fords) if you have:
Heads that flow 300 or more on the intake, displacements of 427 or more, single plane intakes and intake valves of 2.08" or bigger. A cam with .600"+ lift helps too.

Of course on most Cobras they're impossible to fit the hood height anyway...