Depends on the type of spacer, I`ll agree that an open will increase plenum volume and move the power curve up in rpm`s but if your talking 4 hole, esp tapereds I disagree. I put on a tapered 4 hole to try and help fix a cold/damp weather fuel puddling problem I have been having (due in part to no exh heat in the heads/Magnums dont have em). I figured the 4 hole would increase intake velocity, hopefully enough to keep the fuel from puddling and lo and behold it worked . As a small side benefit it picked up a noticable amount of low end punch and it hasnt seemed to hurt it upstairs either, not that I scream the thing anyhow, so IMHO a tapered 4 hole can sometimes be a great benefit, esp for a primarily low rpm/truck setup.Ramjet said:The part I don't get is using a spacer. The higher your carb sits, the worse your low end torque and lauch ability. Spacers are generally used on light cars and especially drag racing engines where you have mucho rpm.
i know this is an old topic. but i have to chime in hopes you read it again. The instructions do not list the adapter as being needed for your application,but if you call them they tell you to use it? i went down that road and they(edelbrock)cant tell you why the instructions dont list it but they say you need it .Pointman51 said:dont know if anybody is still reading this, but I did the whole edelbrock performer package on my .30 over rebuilt 360. I still have the stock heads and stock torque converter unfortunately... But anyway, the performer intake is a spread bore and the matching performer carb is square bore. The instructions stated NOT to use the spread-to-square spacer, so I didn't. I just mounted the carb direct to the intake. What do you recommend?