Fresh 78 la 360, 10 to 1 compression, pro maxx shocker heads, wieand intake, new 4 seconds flat ignition system, roller hydraulic lifters, wont idle below 1600 rpm unless I hold my hand on top of carb, then it idles down sounds great
. 150 psi on all 8 cylinders, used smoke machine cant find any leaks, timed to 18 degrees before tdc, what 4 seconds flat has my new distributor set for, used balloon on end of compression hose to make sure it expanded to get me on compression stroke for distributor rotor pointing at #1 distributor tower
. Tried new holley 750 and new edlebrock 650
Got a 85 318 90,000 miles that I've put new heads and intake and 4 barrel on been running great for years now, know my way around these engines pretty good
. Stumped at the moment looking for any ideas, thanks

 

Just poking at a guess. Chokes? Is the choke hooked up and if so is it coming off fast idle cam on the carb? If you turn the idle screw in does the rpm increase? If it doesn't you're idling off the fast idle cam.

 

Yeah they're both electric chokes, open all the way and they come off the cam, curb idle all the way out, I havent tried hooking vacum guage up, maybe too low a vacum somehow

 

Ok, that's out then. How's about the throttle cable? Is that possibly too tight pulling the throttle open a bit. Maybe disconnect the throttle and all linkage to the carb and see if it idles down. PCV? Is the pcv hose open or is the pcv bad which is causing a huge vacuum leak? i know some of these suggestions sound rudimentary but often it's the little things that cause the problem.