I run a 600 cfm edlebrock performer carb with my performer
manifold,I have been running these for about 18 years my
350 is 240 hp the carb has been very good all these years
i only rebuilt it once because of dirt in carb. when i first put
the carb on i used a spacer on my 327 i threw the spacer
away when i installed my 350 because the spacer would
not seal and it created a vaccum leak. there is no difference
in performance with or without spacer.