Hey Matthew, You have a similar engine to mine, and I started with a 850 DP, and switched back to 770 Holley street Avenger with vaccuum adv (single pumper). I'm much happier with the 770, but did notice a HP loss at higher RPM.
Your question should be answered by your intended usage of the car. Do you want/need every last bit of HP? and are you willing to sacrifice some performance and/or fuel economy for that last bit? My answer was 'no', and I prefer the more street friendly 770 (however, I didn't spend much time trying to improve the 850 DP). Also, Desktop Dyno is not a fair tool to use due to it's known bug of (more CFM = more HP). It WILL show more HP for every CFM you add. You should see what your engine will produce with a 2500cfm carb! :-) Good luck, Mike Quoting Matthew Post <[EMAIL PROTECTED]>: > Hey Guys, > > I'm having my 396 rebuilt and the builder recommended a Holley double > > pumper, either a 750 cfm or an 850 cfm , claiming I would get a bit > more > top end power out of the 850. > > Here what I know about the engine: > 396 being stroked out to 454 > Edelbrock Performer RPM aluminum heads (2.19/1.88) > Edelbrock Performer RPM air-gap dual plane intake > Crower Solid lifter cam - 294/304 duration and 536/556 lift at 110 > centerline > > I think the 750 will probably be a better street carb, but how much > power > would I sacrifice? Any thoughts out there? Anyone have desktop dyno > that > can run the numbers for me? That would be great! Thanks! > > -Matt > > > >
