350 motor has no power

I put in a fresh rebuilt 68' 350 chevy motor with 410 hp. I got it all hooked up, and i have a problem when i try to accelarate, It literally feels like im getting maybe 150ish hp. When i push the pedal down, the
car's power curve will increase slowly, even when i jam the pedal down further, the car just slowly steadily increases in speed at a slow rate.( 0 - 60mph in about 11 seconds). When i hit WOT, the secondaries kick in, and i get nothing except a very slight chug, as if it went lean for a split second. Im using an edelbrock 800 cfm thunder series carb. an edelbrock performance fuel pump (preset at 6psi), hooker headers, i have an HEI distributor with bosh platinum plugs gapped at .45, and 8mm wires. Ive only done the inital timing and it is set at 10 degrees BTDC (with the vacuum canister plugged). I havent determined my total timing yet, but the car seems to advanced quickly when i pulled the carb throttle linkage back, while holding a timining light on the timing mark I have a 2500 stall, and a cam with a 485 lift and around 287/287 duration. So the car likes to idle high, about 900 - 1100 rpms... But basically.... The motor sounds strong at idle, and sounds strong when im driving it. Just no power and poor accelaration. I should be feeling at least 200 more horses. this is my first motor swap, so im a newb. any ideas? thanks for any help or info you can give. ~Scotty
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800 seems a little big for a 350. -- lab~rat >:-) Do you want polite or do you want sincere?
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puked:

Guess that's why a 67 to 69 302 came with a 780:)
Al
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It also came with some solid lifters for that ultra high rpm limit that allowed the use of that 780 cfm. This guys 350 doesn't have a chance with an 800 cfm carb that hasn't been tuned using a dyno or drag strip and maybe not even then.
...Ron

-- 68'RS Camaro 88'Formula 00'GT Mustang
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They also came with 3.73 gears and short tires, and they had zero low end torque.
puked:

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puked:

all
literally
When did 7,000 RPM become "ultra high?" The trick to the 780 was vacuum secondary. The same carb was on the 425 HP 427 and the 425 and 375 HP 396's. And they had the same "ultra high" RPM limit.
Al
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I understand your point that the red line was 6,500 rpm on those cars. Now tell me what the real redline was, if I owned one back in the day I'd run it like I run my hydraulic 5,500 rpm redlined cars... At least 1,500 to 2,000 over that little red line. Balance the motor and your good for 9,000 rpms on a solid lifter 302ci. all day long. You won't be doing that with the big block.
67's #'s were different than the 68'-69' units. Not saying that there was any real difference between the carbs, just that GM used different part #'s. 4150's with the same specs.
What was the trick with the cross ram dual carbs with mechanical secondaries? Most people would say that they were definitely over carb'd.
...Ron -- 68'RS Camaro 88'Formula 00'GT Mustang
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I would set it up with no vacuum advance and total timing of between 36-40 degrees. If you have any cam at all in it the vacuum decreases and the advance is not going to come in. Vacuum advance is only good for fuel mileage at cruising speed anyway. We just helped out a friend with almost the same problem. He put a vacuum advance on a 350 with a decent cam and set timing at 12 degrees. It wouldn't stall the 3500 converter over about 1800 and it only went 13's in the quarter. We unhooked the vacuum advance and set it at 36 total it went 11.60's moved it up to 40 and dropped it down to 11.40's now it needs a little carb work hoping to get into the low 11's ... As far as your carb 800 definitely too much for a 350 ... put a 600 on there and see a world of difference... We have a 383 stroker with dart heads, eagle rods and crank, cam (320 dur) with 292 dur @ 0.050" etc... and only run a 650 no vacuum advance...
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hey thanks lab rat and 69SS for the info, ill definatly try running it today without the vacuum advance and see how it goes. ill also pull out my rod an jet kit and try taking this carb down to its lowest settings. otherwise i got a 600 cfm holley i can clean up a little and toss on. Im hoping this is all an over carbing problem. ill find out soon. thanks again guys
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