Carb spacers on your 351

I am rebuilding my carb this winter and the rebuild kit comes with a spacer in it that I was unsure if I should use or not.
Currently there appears to be two spacers on my manifold. Both are about 1/2 inch thick and I was wondering if I actually need the two spacers or if I should just go to the new one in the kit?

How many spacers are there undr your 4160 on the 351?

Thanks in advance for your insights...
and Happy Holidays.

AWhite70 wrote: Originally my engine had one spacer under the carb. It was a die-cast aluminum casting about 1" thick and had the port for the PCV hose in it.

My carb has the one referred to above. Hot rodders will use carb spacers to boost power, maybe that's where the 2nd one came in.

Fisherman;
I am currently using a 2inch carbon fiber spacer. The Spacer helps move the torque curve
higher in the rpm range. This is why high rise intakes have a 1500-6500 peak power curve.
Lower intakes will make power from off idle to 5500 rpm. The lower the intake and carb the faster you will make your best tourque. I chose the 2inch due to high rpm bare footing, it really helps.
I hope this helps. Brad

I think they used it just for the PCV hose port. Just an idea. Brad

They also use them if it is at a 45 degree slant to level the carb out as the engine bay as it sits at an angle in the boat. Woody at southeast correct craft told me that today. i would use the one on the boat. Does it have four seperate holes? Or one large opening. Four seperate like on my 75 351 is to direct fuel flow to ech intake port better.