I run a stock 4-v intake on my small port 318 heads
I use the felpro HP 1213 (IIRC)gaskets with the heat cross over block with some thin sheet metal block offs. the gasket burns thru in time with out the metal shims.
I would use the LD 340 intake with a 600 eddy carb
I have an LD4B with 318 ports and have run it on 360 heads on a 318 before with the same large port felpro gaskets.
if you run a stock intake with a q-jet on the small port 318 heads adjust the airdoor on the 2ndarys to come in high up in the rpm range for no bog on transition.
I kept tightening mine till the bog went away on the small 318 heads now its a scremer and sounds like a chebby 350