400m carb curb idle?
 

Today I am going to adjust the timing of my engine
but before I do I want to know how I adjust the idle speed
Where do I turn the screw clockwise or counter clockwise?
Oh and what's the idle recommendations? Right now its at about 800 rpm

clockwise raises it, counter-clockwise lowers. Should probably be 550 +/-50

My 77 Ford F150 4x4 has a 400 with 2 barrel 2150 carb and C6 Auto the Ford valve sticker is still on it. It specifies 650 RPM curb idle with the truck in neutral with the idle solenoid wire disconected. I used the screw on the drivers side to adjust idle with a tach hooked up at the coil after the engine was warmed up and the temp guage up at the middle

what do you mean by "550 +/-50" ?
sorry, im new to this stuff:-X18

lol 550rpm idle speed; plus or minus 50 rpm

What he said^. There's usualy a range rather than an exact speed. Some engines idle better at 600, others do fine at 500.