Chevrolet Repair: Engine Stumbles when put in gear, dual exhaust system, rear end gears

Question
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Followup To
Question -
Hello ... I have a 1974 Camaro Type LT with a 350 engine and 350 TurboHydramatic transmission with stock torque convertor.  I just installed the following performance components:

Schneider Racing Cam, .510 Valve Lift
Solid Lifters
Crane Gold Racing Roller Rockers
B&B Stud Girdles
Weiand Hi-Rise Intake Manifold
Swirl-Torque Carb Spacer
Holley 3310 750cfm Carb w/ProForm Main Body Kit
Pete Jackson Gear Drive
Eagle Exhaust Headers
Holley High-Performance Dual Exhaust system

Now, I have to set the idle speed at about 1400rpm, or the engine will stumble and stall when put it in Drive.  Also, if I hold the brake on and try to rev the engine up (as on the starting line at the drag strip), the engine stumbles.  In Park, the engine will rev freely and very quickly.  I know there is a lot more power, I just can't get it "off the line", so to speak.  Any ideas ?!  Thanks in advance !


Answer -
2 things came right to mind, 1, if duration of cam is above, well. better yet, send me all the cam specs, I believe your WAY off target for the stock converter, 2nd, does the dist. have, and are you using the vacuum advance? Also, what rear end gears do you have?

The cam is a Schneider Racing Cam, grind 142-F. Valve lift (both intake and exhaust) is .510, duration (both) is 284 degrees.  The camlift is .340, and duration at .050" camlift is 240.  I do have a vacuum advance distributor, with an Accel Power Coil.  I have a 10-bolt posi rear-end, with 3.50 gears.

Thank you very much for your response.  I work with PC computers as an IT Manager for a small electronics company.  If you have any computer questions, please feel free to ask !

Jim
;>)  

Answer
Dur. @.050 is 240!! No wonder, I'm surprised you can hardly drive it at all!! If vacuum advance is installed on a "full" vacuum port at idle, and when you put it in gear with the "very tight" converter your vacuum signal drops probably to less than 6 lbs+/- 1, the timing retards, engine looses idle quality, to nearly stall condition, it's a "no wonder" it doesn't fall right on it's face!! With the 3.50 gears, I bet it really comes on a about 3800 RPM @ about 80 MPH!! To me, everythings "way out"! A note, please read the book "How To Hot Rod the Small Block Chevrolet" cover to cover, and start over!! I believe it's published by HP Books. Hope this helps!