That's a high initial at 18* for a stock build, sure your throttle blades have enough of the transfer slot exposed???
There is no way I would ever make any carb. idle on the transfer circuit port, NEVER
The idle circuit should and will control the idle mixture and RPM when set up properly
Ultimately the AFR and amount of air allowed into the motor controls the RPM at idle or at WOT
OP, my 518 C.I. 400 block pump gas six pack stroker motor would idle at 850 RPM in gear and gain 100 to 150 RPM going from in gear to in neutral, all on the idle circuit with no vacuum advance with the timing set at 14 BTDC at idle and under 1200 RPM with a big solid roller race cam in it
It had a mix set of original 440 carbs. on that motor modded by C&J Engr, in Whittier, CA
It took a little work and time on my part to get it to work like that so you may need to try and test some different things on yours also
You CAN do THIS
Now, get to work
