Carb spacers

No. Matter of fact, Hot Rod magazine recently asked the same question, & ran a series of dynomometer tests. They concluded that the effect of a carb spacer of any type depends upon a whole host of things. On some engines, ANY spacer did nothing. On others, there was a small increase in torque. On others, a small loss. It seemed to depend on individual intake designs, cams & rpms, but that doesn't explain all their results. Bottom line: the gains when there were some, were of the order of 2%, so unless you're looking for max output & you already have your car/motor scheduled for dyno testing, I wouldn't bother.

A drag racing guy with three (3) GTOs in my neighborhood has a tall wooden carb spacer on his most prized GTO drag racer. It's about 3 to 4" high from the already very tall (6"+) intake manifold. He explained that it's purpose was to insulate the carb from engine heat, i.e. that a lower air/fuel mixture temperature creates more density of the fuel mixture, achieving more power than a hotter air/fuel mixture. The promotional video tape from Jet-Hot Coatings also made reference to an "increase in power" from a cooler air/fuel mixture temperature. But, even taking 200 to 300 degrees off the headers' temperature under the hood only increased power in the range of what Jack was talking about: 2%+/-. Enough to perhaps take a 1/100th off the time in a quarter mile, but I want to keep my carborator under the stock cowling, and definitly not above the roof-line.

P.S. I've also heard that taller intake manifold with longer passageways to the heads creates more Torque while intake manifolds that are squatty, and have short passageways to the heads create more Horsepower.