I agree with Dave. The dual Holley/Webers on my 261 scare me. Have been f**king around with the carb linkage and throttle rod from the pedal through the bellcrank for a couple of weeks now. Finally got it straightened out. Pedal pressure is much reduced and now get both primarys and secondarys open at full pedal. Only problem is my underpowered 1949 drive train and old truck body trying to keep up with the rebuilt monster under the hood! Adjusted the linkages for smooth dual operation and used a magnehelic gauge with pitot tube to set the idle and mixture screws to make the acceleration smooth. Had a lot of doubts early on but the dual Holley Webers work very nicely.

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Country Roads, West (By God) Virginia
http://community.webshots.com/user/geezer