ive been running a 2" spacer for a couple years but was told a 1" spacer would pick me up so of course i had to try it, so at BPG i tried it, i did back to back runs first run with the 2" spacer then swapped it out for the 1" spacer it was only about 20 mins between the 1st run and the 2nd run, i picked up a full tenth and a couple mph. i did nothing but swap the spacers, no jet changes, only had to adjust the idle. the car does idle and respond different to each spacer.
Last year I had a chance to attend part of the engine master's challenge, and there was a guy that built a small block chevy with a TBI set up. Due to a time constraint before arriving, he had used two pieces of 1/2 plywood with sealent for a front cover. It held together on all his dyno pulls. I thought it was pretty neat.
Regarding the plywood (or maybe a solid piece from a 1 or 2 x6) as a spacer--the good thing about wood is it's cheap. You can make your own custom spacer in any configuration you need. JUST PAINT IT BEFORE INSTALLING IT! Paint it silver or black or the color that the rest of the engine is, and it won't stand out so much or look like "garbage" in there. Wood is a natural form of what synthetic phenolic resins try to imitate. It has superior heat-shielding properties. If you don't have $200+ to spend on a high-end spacer, this might work fine. My 2 cents. --Chris
