Thread: dual quad intake

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I have a 37 chevy truck with a built 305 bored .060 with a modified cam. sanderson headers, performer intake and a 600 carb. I would like to go to a dual quad intake with either 2 500 cfm edelbrocks or 2 390 hollys. Which would work or is this to much carb for this engine?

your single 600 is plenty for a 305, if it's bored .060 that puts it somewhere near 315 so this is still plenty.

give me more info on the cam, tranmission and usage of your ride I would say its is too much either way, as it is a healthy 305 has enough trouble making low torq, a tunnel ram usually has nuthing bellow 3000 rpm and or a 305 hardly needs that 600 thats on it you can use this formula to see what it really needs it will probly surprize you cfm= rpm x displacement (divided by) 2 x1728 should give you approx. what cfm depending on the max rpm usually seen by your motor.

rattymodelA The 305 is running a crane cam 210/216 duration with a 350 tranny. I had a 500 carter on it before I bored it .060 and the 600 really made a difference. The 9" ford rear end has high 2:76 gears which I'm leaving as a like to travel alot. I was thinking if I went with the dual carbs I would use progressive linkage and only run one carb and open the other at WOT.

Progressive linkage might work good in your case. Would it be worth it, how many times a day do you floor it?

Who me? Floor it! Honestly about 50% of the time.

Sounds like a dual quad with progressive linkage is for you, chevy 37. I don't know if you can mix/ match carbs like 500 cfm edle preformer and 600 cfm preformer but if you can i would go with this set up, one fair sized one and one smaller carb, this should work best if possible.

Originally posted by chevy 37
rattymodelA The 305 is running a crane cam 210/216 duration with a 350 tranny. I had a 500 carter on it before I bored it .060 and the 600 really made a difference. The 9" ford rear end has high 2:76 gears which I'm leaving as a like to travel alot. I was thinking if I went with the dual carbs I would use progressive linkage and only run one carb and open the other at WOT.

Okay well the cam, gears and if the th350 still has a stock converter or only a small stall speed your going to have a big gap or bog to get it in its power band those gears are going to hurt you too sounds like you drive your ride a lot and like the mileage and cruiseability, I wouldn't recommend this because everytime you have your foot in it the boging effect will be evident until around 3000 rpm but its just my opinion. Sometimes doing it wrong gets it right if you do decide to do it, go with the holley 390's they are very tuneable for the t ram set up running off one most of time will probly help your mileage a little and may be just small enough and the wide range of jets available you can tune it to keep the 305 happy when your cruising. It is a nice look but I have been there and done that with the driveability woes fouling spark plugs and poor performance around town. Realistically these t rams are for a 2-2500 car with 10:1 cr, a cam with around 290-300 degrees of duration anywhere from .490" up lift, automatic with a high stall 3k to 4k depending of motor or a stick and at least 4.10 gears, this is the combo that I have seen work with this set up. Another opinion I will ad all my buddies with chev powered rods run junk yard 305's in all different forms and the best, reliable and fun set up is a three deuce manifold with the outside two carbs non functional and running either holleys or stromberg 97's killer looks, stock performance, 0 head aches. Hope this helps I like things that drive good and would hate for you too shell out the cash for the carbs and such to do this swap and find out that you can't endurance run you ride anymore because even a super coil and an msd can't help burn the fuel a t rams dual quads can inflict on a sbc's plugs.

Hey guys thanks for all your info. Even an middle age guy like men who has been around cars all his life still doesn't have all the answers. I agree that the dual quads are to much for my engine and I do have an intake with 3 two barrel rochester carbs that I will probably use. I think I will have the first two running at all times and leave the last one for my heavy foot. Bart

Thanks street Your right on the set up on the carbs. I had a 348 with 3 duces and if I'm not mistaken I did run just the center carb until I wanted more juice and had the other two kick in. Thanks again Bart