Spark Plugs Ahhh

[DeputyDan]

Getting ready to throw the engine in and piecing the final puzzle parts together. I am looking at shorty plugs that will clear my headers. I have E-street cylinder heads which call for a 3/4 inch reach. I found some accel shorty plugs at summitt that meet that criteria but they have a whole world of heat range selections. My build is a mild build 350 with 64cc heads, flat top 4 relief pistons, lunati 60102 cam, and edelbrock 600cfm carb. I don't know a thing about spark plug heat ranges and everything I can find deals with racing. Can anyone give me an idea of what heat range to go with? This truck will be a daily driver. I am thinking my compression will be around 9.5 and around 330 horse. Also can you mix long and short plugs? The reason I ask is because there are just two plugs with clearance issues.

Also while I am here I was able to pick up a 2000-2200 stall for free and would like to use it with this setup. I always heard to use a stall that is at least 500 over the initial operating range of the cam which is 1400. Do you think this will be ok for street use? Thanks for all your help guys!