I ran that intake after I had an old holley street dominator single plane on it. Here is my take, yes lower rpm did have more power and it did idle better but after 5,500 - 6,000 power nose dived compare to the old holley intake. I could take off faster from a dead stop with the RPM but I missed the wot scream the holley had....that was the last intake I used up to the D66 and then my 318 spun a rod bearing and I got a 340 short block to replace it..had 360 MP heads already on the 318...I never ran any other intakes on the 340 block
I had no room to try any spacers on the RPM intake
