Here is the scenario; 431 BB 11 to 1 comp., Edelbrock oval heads, Crane mech. flat tappet (Intake .567" and 238' @.050", Ex.haust .589" and 248' @0.50, 114' lobe separation, 14-15 inches of vacuum @ 1000 rpm idle). I am currently running a Performer RPM manifold and 9381 Holley 830 cfm. It is a great combination for both power and throttle response, but runs rich @ idle. My problem is that emission standards for my car have been tightened again. Previously I could sneak thru on an idle test (873 ppm HC and 4.09% CO limits) now the required load test drops these levels even further (278 ppm HC and 3% CO!). A vacuum sec. carb might help, but I figure it is time to get in the 21 century and go EFI. Hopefully I will gain some HP/midrange and solve some minor issues (cold start/running and stalling under extreme braking) along the path to emission happiness. My questions are;
Which product is better, Edelbrock, Holley or other and why.
Has anyone done a similar conversion in a state or province with emssion testing and what were the results?
As usual, thanks in advance for any thoughts or suggestions.

 

great site for this question. http://corvetteactioncenter.com/foru...&postid=122448

 

I posted a response to your post on chevytalk. In addition I'd like to recommend the cmdr950 or FAST over the edelbrock for your application. Both FAST and 950 gives you the ability to load an "emissions calibration" when it is time for testing. Edelbrock has a PROM and only lets you fine tune with a hand held controller. Edelbrock will also not run closed loop below 1800 rpm. 950 & FAST lets you specify the closed loop rpm.

 

Thanks for the links and responses. I agree that a programmable EFI is my best chance at beating these standards and based on your input and info from the Chevy Talk forum, the 950 Commander is the most suitable and readily available option. Zwede, your EFI project mentioned milling 0.6" off of the TB base of the Holley manifold. I also have an L88 hood and want to confirm what your final clearances were to determine how much, if any, milling is ultimately needed. Are you running the L-88 fresh air components (base, flame arrester screen etc.) and/or some form of air cleaner? Thanks again for your help and information.

 

I'm running the factory style cold air box with flame arrestor etc. It is a little tighter than it should be, even with 0.6" cut off. I should have cut the top at an angle and I would have gained more room. Probably about 0.7" front, 0.5" rear would have been perfect. As it is now I have to use an angled spacer between the TB and the aircleaner base to get the correct angle.

I don't see how you could fit it without cutting. The aircleaner base will hit the bottom of the airbox.