therm quad size

Rumblefish is right. Any TQ will need tuning, BUT they are more forgiving than most other carburetors. It is true that you can remove a TQ from a 440 and run it on a 318 with GREAT success. this is one reason Chrysler used them. They can be used on a wider variety of engines than most carburetors. This doesn't mean that 440 TQ will be tuned properly for that 318. Now, on a wramed over or hot 318, that stock 440 TQ would probably be a frikkin tire roaster. Also something else to keep in mind. If you're gonna run a warm or hot 318, use the 850. Here's why. The two carburetors while similar, have a very different fuel curve. What that means is, the 850 TQ will have MORE available fuel all the way up to the max it will flow on an engine. In other words, it's a richer carburetor throughout the RPM range, not just in total CFM flow. These points are all what makes the TQ such great carburetors. although they have many adjustments and can be daunting to figure out, once you see and understand what each adjustment does, you wanna beat yourself upside the head because they are so dead simple. If carter would start making the old Strip Kits for them again, I think you'd start seeing more of them in serious competition and perhaps eclipsing some of the Holleys. They are that good.