guys i have a 1969 442 and i need some help.i will give all the info i can so if i need more info please be patient and i will advise as i receive .i bought a demon 725 on the recom. of our local hot rod parts shop.i am having issues.first off about the car 400 motor ,4 spd, two and a half inch exhaust.slightly better than stock rebuild thirty years ago unleaded fuel yes so no info on cam that i can find. i purchased a mondello intake for this car and demon carb. msd ignition but thats about it. car starts and idles fine sounds great but. fuel odor is horrible at idle and under load bogs down before pickup. im a novice so i will have to ingest any info given to me by research just really looking for a good place to begin. run fine on freeway once up to speed . thanks

 

Which MSD are you running? What is your timing set to? Which Mondello intake? Did you set your float level and a/f mixture on the carb?
http://documents.holley.com/lit407rev3.pdf

 

First thing I'd do is take that Demon apart and check it out. Barry Grant went to *&^% in it's latter years and the carbs were crap. Every one of my three Demons needed work to make them right.
From bad castings, loose butterflies, hodge podge of different air bleeds in the same carb, etc. I could go on but you get the picture.