My GTX had a 780 DP on it when i bought it. Made good power but didn't stay in tune. It was old and leaked and had other isues but over all not a bad carb. Milage was poor. Went with an 800 eddy thunder series. Good carb, took a little to get the stumble out as car has a big cam. Milage was decent, throttle responce was good but lacked that kick in the pant's you get when you open up a spread bore and those big secondaries come in. Just switched to an 850 TQ and love it. Milage is a tad better, throttle responce is crisp and at WOT hold on. Over all i prefer the TQ to any other street carb.