maddmann313 Posted September 13, 2010 Share Posted September 13, 2010 A friend of mine told me that a Holley 750 cfm double pumper would bee too much fuel for a stock 350... Is this true? Quote Link to comment Share on other sites More sharing options...
Winston Wolf Posted September 13, 2010 Share Posted September 13, 2010 It is probably on the big side, but if jetted correctly it will certainly work just fine. You may have crisper throttle response with a smaller carb, but I think people worry about it way too much, as they don't know what they're talking about. If you are ever planning on doing anything to the engine, may as well only buy one carb. Tell your buddy to get a 500 and you get the 750. Then read this article. Carburator Size Testing Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted September 13, 2010 Share Posted September 13, 2010 Adam, several years ago I did some A and B testing with a mild 350/350 car for this exact issue. The carbs I tried were a 750 vacuum Holley (3310) and a 600 vacuum Holley (1850). While the 3310 can certainly be used the drivability with the 1850 was tons nicer and more responsive. If it's a street geared stock converter automatic car I would stay away from a double pumper, the motor can't handle it down low. Dave Quote Link to comment Share on other sites More sharing options...
maddmann313 Posted September 14, 2010 Author Share Posted September 14, 2010 I mean its going to be a daily driver and im not going to be deep in the throttle(well not always! ) The carb is a 3310 so for it would be good? Also another one of my friends said to take the plastic pieces on the secondary off because no one uses them. And while im on the carb subject what would a 1" spacer plate do? Quote Link to comment Share on other sites More sharing options...
monte70car Posted September 14, 2010 Share Posted September 14, 2010 Does the carb look like this? its a 750 hp double pumper or does it look like this 750 with vacuum secondary. I'm not sure what piece your friend is talking about taking off on the secondary. A double pumper will use two pump cams on the throttle arm, vacuum secondary uses a vacuum pod to open the secondary of the carb. Quote Link to comment Share on other sites More sharing options...
Winston Wolf Posted September 14, 2010 Share Posted September 14, 2010 3310 is a vacuum sec carb, not a double pumper. Just run it without doing whatever it is your buddy told you to do, if you have it already, it will work just fine. I would not run the spacer on a stock engine. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted September 14, 2010 Share Posted September 14, 2010 it will be fine, a smaller carb would be better, but you already have the 750...run it Quote Link to comment Share on other sites More sharing options...
maddmann313 Posted September 14, 2010 Author Share Posted September 14, 2010 Yes it does looks like that... And the intake it the stock, for the q-jet and has the small holes and the bigger holes in the intake. Also why not the spacer plate, what would it do? Quote Link to comment Share on other sites More sharing options...
Winston Wolf Posted September 14, 2010 Share Posted September 14, 2010 Well, if it's a stock qjet spread bore manifold, you will have to run the adapter plate because the bolt holes don't match up otherwise. No need to overthink things on a stock engine, but an open spacer generally helps the HP on the top end and may reduce some torque in the low/mid range. Quote Link to comment Share on other sites More sharing options...
maddmann313 Posted September 14, 2010 Author Share Posted September 14, 2010 what about this one? http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=400070992500&viewitem=&sspagename=STRK%3AMEWNX%3AIT Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted September 14, 2010 Share Posted September 14, 2010 linky thingy Quote Link to comment Share on other sites More sharing options...
Winston Wolf Posted September 14, 2010 Share Posted September 14, 2010 That won't work. You need one of these my man.... Spread Bore to Square bore adapter. Quote Link to comment Share on other sites More sharing options...
maddmann313 Posted September 14, 2010 Author Share Posted September 14, 2010 What if I put the intake on it with the spacer plate? http://www.firstgenmc.com/ubbthreads/ubb...7995#Post277995 Sorry for not posting links right im doing this mobily and its kinda hard Quote Link to comment Share on other sites More sharing options...
Winston Wolf Posted September 14, 2010 Share Posted September 14, 2010 With that SP2P intake you shouldn't need a spacer plate, but you could use the first one you posted on that if you wanted. Quote Link to comment Share on other sites More sharing options...
kc8oye Posted September 14, 2010 Share Posted September 14, 2010 you absoultely do NOT Want that double pumper. With a stock engine, stock converter, stock gears.. that double pumper is just gonna hose gas down in the engine and make it run awful. Quote Link to comment Share on other sites More sharing options...
maddmann313 Posted September 14, 2010 Author Share Posted September 14, 2010 If thats not a good carb what do you recommend? Quote Link to comment Share on other sites More sharing options...
monte70car Posted September 14, 2010 Share Posted September 14, 2010 The vacuum secondary 750 would be idea. I'm not sure why people make the double pumper sound like its gonna suck gas when you will run off the primaries until you mush the pedal to the floor and you open the secondaries. If you go to Holley's website you can see what type of carb they say to go with. Quote Link to comment Share on other sites More sharing options...
Monte72Carlo Posted September 14, 2010 Share Posted September 14, 2010 I Personally run a holley/proform 750 double pumper on my 350. I have no problems with it yet, mind you it's not 100% tuned right yet. I have some slight modifications to my 350 though such as vortec heads, 10.5:1 compression ect.. I don't know if this helps or not. Garrett. Quote Link to comment Share on other sites More sharing options...
kc8oye Posted September 15, 2010 Share Posted September 15, 2010 because ert, the double pumper forces gas into the motor whether it's ready for it or not.. evertime he opens the throttle, all 4 corners are spraying fuel in.. that's fine for a hard launch in a built car, but is gonna run like CRUD on the street. Holley isn't kidding when they say not to put double pumpers on automatics (w/o a lot of stall) or heavy cars. 750 is way to big for a stock engine. (with vac. secondaries this isn't a big deal, other then hurting drivability a bit) I tried a 750 on my mild 350 and it hauled the mail awesome, but was really lacking when just cruising.. 650 vacuum secondary will MORE then cover your needs. stay away from those 600's.. they are single feed and can cause you headaches down the road. Quote Link to comment Share on other sites More sharing options...
Jared Richey Posted September 15, 2010 Share Posted September 15, 2010 If you're wanting more power I'd go with the Holley. But not a Double Pumper, way to much for a Stock Engine. I'll mention this also...If you want great driveability, Gas Mileage and still good performance IMO you cannot beat a good working Quadra-Jet. Quote Link to comment Share on other sites More sharing options...
Winston Wolf Posted September 15, 2010 Share Posted September 15, 2010 I mean its going to be a daily driver and im not going to be deep in the throttle(well not always! ) The carb is a 3310 so for it would be good? Also another one of my friends said to take the plastic pieces on the secondary off because no one uses them. And while im on the carb subject what would a 1" spacer plate do? Read the thread guys. It's not a double pumper. It's a 3310 vac secondary.... Quote Link to comment Share on other sites More sharing options...
maddmann313 Posted September 15, 2010 Author Share Posted September 15, 2010 okay so with that edelbrock intake and a holley 750 vacuum secondary should be fine? Quote Link to comment Share on other sites More sharing options...
Andy's Auto Posted September 15, 2010 Share Posted September 15, 2010 Stock 350? Nothing says I love you like good running Rochester Quadrajet. Small promaries for excellent throttle response, big air valve actuated secondaries for good mid range and top end? You not feeding a rat, you are feeding a mouse. Wanna have an awesome torquy beast, thing 2 barrel. Sounds like you want to drive the car. I put up with alot with my 71. Fast but needy. Idle is tolerable at best. Get just over 100 miles to the tank. Likes premium. Compliments, fun, but a 500 cube engine has its downers. Oh yeah, it runs 12's. And it has a 4779 Holley 750 double pumper. Enjoy what Chevy gave you. There is no way a 4779 Holley is gonna have near the driveability as the stock carb. On a stock engine. Andy Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted September 15, 2010 Share Posted September 15, 2010 The SP2P intake is a older design Small Port 2 (dual) Plane. It is a mileage manifold designed to run to around 4000 rpm. If you have a vacuum secondary 750 it may not be optimal for the manifold but will work because of the secondary setup. Quote Link to comment Share on other sites More sharing options...
kc8oye Posted September 15, 2010 Share Posted September 15, 2010 Read the thread guys. It's not a double pumper. It's a 3310 vac secondary.... A friend of mine told me that a Holley 750 cfm double pumper would bee too much fuel for a stock 350... Is this true? looks to me like he said it's a double pumper? manmann: get a SIX-fifty Vacuum secondary, that's all your engine needs. Quote Link to comment Share on other sites More sharing options...
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