they do. i have built alot of chevy small blocks and in my experience i have had alot of hot start issues and some trouble dialing in the idle/fast idle circuits. edlebrock carbs are good for very mild motors out of the box but take a bit of fine tuning... when going to WOT there is alot of times ive had them bog. but when you roll on the throttle theyre ok with no bog (once dialed in).. i havent done eddys on SBF's but if you already have a holly go thru that if its the right size and slap that on and see what happens.. eddy's are super easy to rebuilt if it's not too far gone. if there is shaft play on the eddy, id toss it. not worth re bushing the throttle shafts IMO. if you have hot starts, throw a spacer under it, route the lines best as u can away from heat, check the choke operation, then the A/F mixture. twist the two screws in all the way, then back them out 2.5 turns out. thats the best way to start messing around. do it with a vacuum gauge and stop when you have the best vacuum.