Just finished my 383 all specs are in my sig running 11.5:1 compression. I have an edelbrock 670thunder avs carb primary jets are .095 primary .098 secondarys .065 x .047 rods with silver springs. part throttle seems fine but as soon as i punch it i get the initial surge of power then the car dies. im guessing its going lean i adjusted the secondary air valve to open sooner so its not bogging when i punch it but right after the secondarys open the motor shuts off. any thoughts on what jet size i should try?
this is a spread bore design as well so im guessing the primary jet is too small

 

Thunder AVS spreadbore? 670 CFM? Eliminating bog by opening the secondaries sooner?

None of this adds up.

 

i was told it was a 670cfm when i bought it but looking at edelbrocks site its listed as a 650cfm. i had a 600cfm performer on my old motor and it always had a bog cause the secondarys opend so late. i tuned the adjustable secondarys on my new carb to open sooner so it makes a smooth transition but a second or so after the secondarys open on a wot punch the motor dies. the 650 version that i have is a spreadboar "Q-Jet" style small primarys up front large secondarys in the rear. I decided it would be a good setup for my stroker cause the small primarys give me some of my mileage back with the large displacement and it really tamed my idle. I have it idling damn good at 750rpm out of gear and it only dropps to 700rmp in gear. My buddy that had FI on the motor had trouble doing that.