my Low dollar 318 hop-up project
'73 cast iron 340 intake. Bought here on FABO, shipped to my front door for 60.00. I chose this one in particular for a couple of reasons and I will list them in order of importance:
1). It Works!!! I've done drag strip test on a mild 340 and mild 360 with the cast Thermoquad intake vs. the LD 340 eddy (one of the best), the Eddy performer intake, and the M1 single plane intake. You give up nothing for flow throughout the rpm in a mildly built small block with the '72 or newer intake. I've personally watched the cast intake get into the 10's in the 1/4 mile.
2.) It's in the budget!!! I usually do not like to spend more than 40 on one of these. I went 60 shipped with this one due to the fact, if you haven't noticed, the carb mount area has been "hogged out" (can be done with a 20 dollar dremel, or a couple of 5 dollar files) and it's really clean. The ONLY reason to "hog out", or "open up" the carb mount area is to make it work better with the square bore carb. If you are going to use the Thermoquad, it is not necessary. This intake is a spread bore intake and loves the Thermoquad carb.
3). Second hand aluminum intakes have greater risk. They can warp and be harder to seal, striped threads, and usually about double the money. Their biggest advantage is weight, the only downfall of the cast intake....
Some square bore carbs may need the adaptor I have pictured to be sure the square bore carb seals (no leaks). 5 dollar item at swap meets, or 20 bucks new. Not sure what carb I'll be using, still scrounging. Hoping not to spend the "5 bucks" on the adaptor.... lol