Quote:
Originally Posted by bigblockv6
It will definitely make a bigger improvement once you machine the manifold. Many years ago I tried the 4 to 2 adapter and the results were abysmal, the idle would fluctuate and when the secondary's kicked in it would stumble for a couple of seconds.  I suspect it was a very poor quality adapter that leaked vacuum. All in all there is only so much fuel that you can squeeze in a small opening. |
Mine idles perfectly, but has the same problem when the secondaries kick in....In 4th if I stuff it to the floor the thing jerks and rattles then clears up. lol I suspected either no vacuum advance or to much fuel for a small opening. But if I quickly ease into full throttle it responds fine. So for now I've left it cause its running so good. But when I get my 66 done I'm gonna get into this one. The improvement was major over the 2 barrel. With the 2 barrel I couldn't even rev the thing past 2500 rpm to shift or it seemed to take a month of sundays to get there...hence why I'm sure that old carb was plugged up. Lugging it into 4th proved faster than reving it. It actually would accelerate faster when I had the truck loaded down, least it sure felt that way.lol But once the 4 barrel went on, shifting at 2500 has been the best rpm. And when I split the exhaust, 2700 is now a good rpm.