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need help with 350 carburated

buffblazer

buffblazer

1/2 ton status
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Jan 5, 2005
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Location
Fort Collins Colorado
alright i gotta rebuilt 350, been bored 30 over and has an rv cam in it. 600 cfm edlebrock with all emissions un-hooked or plugged off. now i read the post about the 350 tbi improvements and i was wondering what i could do for my carburated engine. gas milelage is not the major concern right now, but i need power. im running 33'' big O x/ts with 4:10 gears and a sm465. now i have tuned the carb to the best of my abilitys with new jets, rods,springs, all recomended by edlebrock for the best fit for my carb at my altitude. and a rebuild kit because the carb is over 8 years old, new plugs, wires, air filter, timing is set at 12 degrees and i cant even get the tires to spin when i dump the clutch and its a dog when accelerating. so what can i buy, replace,and adjust to make my truck make the most power, i understand i might need a bigger carb, but what can i do thats sorta cheap, and what can i do thats more expensive up to about a $1000, because thats all i got for my truck budget. thanks for all the help you guys can give me.
 
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i have the K&N already, and exhaust sounds like a great idea, what kind of improvements am i looking at with the intake? keep them coming guys i need help with this.
 
I am not sure what type of improvements are made with an intake maybe 10 to 15 HP and a weight savings of maybe 5 lbs. I have used a few on engines I have swapped intakes before and have felt a noticable seat of the pants difference.
 
is it possible your catalytic converter was damaged by the old engine and is plugged?
 
how about more specs on the engine combo, and cam?
You shouldn't need a bigger carb, unless you want to run 5000rpm or higher.
 
My exhaust was an issue before. I suspected that the cat was plugged, but was suprised to find it was exceedingly clear. Seems that it had puked out all of its guts...and deposited them firmly in the muffler:haha:
 
all i know about the engine is it was a a rebuilt 350 long block from marshal engines that was bored 30 over. my dad put an rv cam in it, and i dont know what kind of heads or rods or valves it has, he slapped the old 305 intake on it i belive, and then a 600cfm edelbrock. the exhaust is a single flowmaster, the cat came apart one morning and shot honeycomb crap out of the tailpipe. it has a 4 hole carb spacer, and a K&N, but im thinking i might have a vacuum leak because you can hear a whistling sound, and i have a fuel leak on the driver side of the carb, but i replaced all the gaskets and it still whistles and leaks. also when you crank the throttle, the flaps open and it seems like it starts sucking air and stumbling for a split second before the fuel picks it back up.
 
Well I think you know a serious vacuum leak (like the one you hear) has serious performance implications. Track that down, by spraying carb cleaner around the carb base, the carb body, the metering blocks, or jet plate, check all vacuum hoses etc. Get rid of that leak then go from there.
 
first things first, like the guys said, find that vacume leak, kinda critical for a carbed engine that relys on vacum to operate.

leave the carb for the time being, its plenty big for a moderate performance engine.

i agree whole heartedly with the header swap, so far adding the edelbrock TES headers to my IROC was the most impressive seat of the pants improovment ive done. and only cost about 350 bucks.

the 305 intake manifold prolby isnt helpin, id also agree with everyone here saying to swap out to a high performance manifold. those are goin for anywhere from 150-300 bucks.

other than that, id also recomend stepping up to an aftermarket ignition system like the crane cams HI-6 setup. anything with a multispark capasitive discharge setup and a higher power coil will make more power and probly increase gas mileage.

i think if you fix the vacuum leak, upgrade the intake and exhaust to allow the engine to breath, and step up your ignition, youll be very pleased with the results, and you should still be within your 1k budget.
 
and i could have sworn that there was no difference in a 305 and a 350 intake, only differences were supposed to be the piston diameter, cylinder diameter (obviously) and the heads.......:doah:
 
the 305 intake is gonna be a cast iron small port factory peice, with rough ports and bad flow. But you are right, the 305 and 350 peices are for all practical purposes identical.

i was basically sayin the aftermarket peice would flow better and make more power, and shed quite a bit of weight actually.
 
thanks guys yall gave me a lot to start with, i will probably get the exhaust done within the next week or so. but as for the vacuum leak, i have sprayed everywhere in the past, and still have not found the leak, but of course i will check everything this weekend again to make sure. thanks again and i will keep yall posted
 
Trace each vacuum line from carb or intake to its final location, which may include the vapor charcoal canister behind the radiator support. Make sure you find that leak or every change you make will suffer for it. Just realize that your engine is running lean with a vacuum leak.
 
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