4bbl/linkage questions

I use an MSD 6AL, with a 6500rpm limiter chip. Will never over-rev! Also I am looking for a carb with vacuum secondaries, as I'm a pretty chill driver. Also, I'm not certain that it will make much difference which brackets I use, as apparently the lokar kit will mate to both! I wish I had a good parts guy, closest vintage-friendly parts broker is an hour away in the usual San Francisco traffic :/