I'm getiing symptoms of heat soak issues on my 350 with aluminum intake and stock Qjet. What type of phenolic spacer is better, pros, cons? Does height matter if it fits inde the hood, taller better? Some have the holes all the way thru some are open: these are only 1/4 inch: http://www.ebay.com/itm/Rochester-P...ries&hash=item35c5cc68ec&vxp=mtr#ht_244wt_748 35 bucks good? http://www.ebay.com/itm/Rochester-P...ries&hash=item35c41aa88a&vxp=mtr#ht_244wt_748 1inch http://www.ebay.com/itm/Speed-9136-...ies&hash=item53f6d5140f&vxp=mtr#ht_2327wt_768
Get more opinions than mine, but as a general rule, open and taller = better for higher RPM; 4 hole and shorter = better for lower RPM.
At the Jegs website they have wood spacers for the Q-jet and they are 4-hole. They have them in 1/2" and 1" the wood will keep the heat out of the carb. Both will more than likely give you some more power.
Here's the HOT cool item. I'd use them if I had the space. My hood is very tight with the SP1 intake. When I ran the B4B I made my own 4-hole spacer out of plywood. That or the phenolic is best but this setup looks even better. I saw this stuff at Carlisle: http://www.coolcarb.com/ You of course have blocked all your exhaust x-over heat passages, except for maybe a 1/4" hole if you drive in cold weather? Gary, I'd say tall is good in 4-hole spacers also, builds velocity down low. 1" should fit under your hood with the right drop air cleaner.
