What does a carb spacer do and should I put one on my 360? Thanks

 

A carb spacer theoretically does two things. First, it reduces the intake charge temperature by acting as an insulator between the intake manifold and the carb. A cooler charge is a denser charge, which will result in more power.

Second, it increases the velocity of the charge by effectively lengthening the runners. Higher velocity means better torque and throttle response.

I don't know how significant the effect is, but there is some effect. Spacers are also relatively cheap, so they're worth a shot. If your motor seems to be sluggish off the line, with poor throttle response, and you've already given it a good tune up and set the timing right, a 1" spacer would be worth a shot.

 

The insulator also helps reduce fuel percolation during heat soak.

 

Also

An open spacer can-
dampen the signal (intake pulses) thus leaning things out
reduce standoff ( reversion)
make changes in direction smoother
increase plenum volume

A 4 hole can
add stability to the flow below the carb
increase runner length

 

I recently dyno'd my 408w that will be going in a street/strip car. The carb spacers are definitely a great modification, it madee 5hp more at peak, but around 10ftlbs more torque from 4000 to 5800, that's a ton of performance for a $25 spacer.

 

I'm starting to work on my '53. It has what I think is a 352 in it. I know that it has a carb spacer that is hooked to the cooling system. Is that unique to any type/year of engine?

Thanks