Ive bought an AED 1/2" open wooden spacer for my 440 to keep the heat out of my carb. 440, lightly ported aluminum sidewinder heads, eddy rpm intake, eddy 800 thunder avs carb, 1 7/8" exh, 10.5:1 compression, 254@50 duration 554 lift single pattern, 4000 stall, 4.10 dana. 4000lb car.

Im doing a little research on spacers and Im not knowledgeable enough to predict if a 1" tapered spacer (or other size) from wilson will improve my combo or just do the same job as my 1/2" for 4x the price. I would just buy one and try it if it wasnt so expensive.

There's really only one way to know what it will do on your exact combo.

maybe Ill ask Santa for one this Christmas

On the dyno a merge type spacer almost always add a little power. If you have the room I'd run one on a street car but I'd probably use a phenolic one to keep the carb a little cooler.

When you say merge do you mean a combo spacer that starts as a 4hole then goes open?

I have a 71 charger with no hood at the moment, so anything will fit lol. But I will be getting a fiberglass lift off power bulge hood so I think I can run a 1" spacer with no problems

Most running the taper/contoured spacers have said it leans out the mixture to require a carb change/adjustment...........

I think any time you add plenum volume with a spacer to a Mopar BB wedge motor the car will go faster I have tested a 4 hole two inch tall and then a open two inch and both made the car FEEL better, this was street testing On testing a two inch open spacer on a Dominator flange intake and then the same hieght Wilson reversion spacer they both made the same HP and torque on a old Weiand Team G intake with no other changes
Taller is better

I'm not sure that a 4 hole merge spacer is going to be the hot ticket sitting on top of a dual plane manifold.......... But it's easy to try.

I recently put a 1" 4-hole phenolic spacer on a Edelbrock Performer intake on a propane fed SB-engine.
It really woke up the off-idle to low rpm range.
I also put a slight chamfer to the underside of the spacer to help transition the mixture flow into the large intake plenum below a bit better. Was more a gutfeeling move than an actual flowtested modification.