carb to intake

Why am I getting a high rev in park? I need to lower the idle….. any advice? Rochester 2 barrel Already tuned by a diesel mechanic . I am a new 🐝 when it comes to carbs. Dez

Hi Guys, Am I missing a spacer between my GM 2bbl carb and stock intake, like I had on my 327 4bbl? The bolt pattern on the intake measures 31/4" left-to-right and 1 7/8" front-to-back. The carb bolt holes measure 3 5/8" left-to-right and 2" front-to-back. Thanx, Dean