Putting my 440 back together after a new Hughes Whiplash cam. Wondering if the metal carb spacer (about 3/4") is going to add anything. Added a Edelbrock Performer manifold Holley 770 Street Avenger. Have about a 9:1 CI. Hedman Headers. 3"TTI exhaust. Should I put the spacer back on?

It adds some horsepower. On recent dyno test had one had 6 horse.

from what i've read the metal spacers allow heat to transfer into the carb ,sometimes even boiling the fuel....(probably extreme cases)but there are many different uses for different type spacers to resolve problems and gain hp/TQ

Run a Shear plate if you are going to run a spacer, I have not dyno'd any but they are reported by others on moparts for 7-25 depending on the combination. I went with the magnafuel, they were cheaper and about the same as the Wilson's for my 572 Hemi. Tim

I guess I'm still not sold that is is worth putting back on??? Has anybody actually run with one with any results? This is strictly a street car by the way. Thanks

Sometimes carb spacers don't help at all.

There was one with a guaranteed gain of X hp. Didn't help one bit.

It all combo dependent.

I went from a 1" aluminum 4 hole spacer to an Edelbrock 1" phenolic 4 hole spacer. Difference is night and day. Less throttle response to gain the same speed with the phenolic spacer. Shifts about 400 RPM sooner when granny driving shifting from gear to gear. Carb is running cooler because of it! I couldn't believe the difference with the seat-of-the-pants dyno.

the las guy beat me to it, i was just going to say if your going to run a carburetor spacer at all run a 1 inch 4 hole phenolic carb spacer, they are awesome and well worth it.
I run a 1 inch 4 hole phenolic carburetor spacer on my 360 magnum with a dual plane edelbrock rpm air-gap intake and a 600cfm manual choke edelbrock performer carb and it makes a huge difference in throttle response, gives the low end a major boost and it also starts up way easier with it on compared to with it off. I have heard the 1 inch 4 holem phenolic tapered spacers are even better. I think wilson makes them....

I run one of these (best price I could find). It's 1/2" phenolic material. I had to open the holes a bit for the 825CFM demon carb I run, but it should work fine on your carb.

I bought it specifically to block heat from getting to the carb, and it definitely helps with that. It also made my engine run better, so that I could close the butterflies at idle from where I had with no spacer, which made it run on the idle circuit more and it was easier to tune. Seems to have more torque now too. Probably the best $13 I've spent.

http://www.ebay.com/itm/130709764613?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

I have not realized any measurable hp increase adding a small 4 hole spacer to a dual plane intake. I have increased power every time I've added a open hole to a dual plane intake. Of course, it will depend on your power level and which manifold you have. The difference gets greater as the power level goes up. At your power level, using a Performer (not RPM) I would guess that you would see an increase in power in dyno or track results with an open spacer.

Using an insulating spacer (wood, phenolic...) is alway a good thing.