SBC the exhaust temps from some exhaust ports are high. I had a pop in exhaust for a couple of days and got to wondering if the engine was running rich. Today I used a temp gun at work and pointed it at each pipe coming out on the headers. From the left front port to the left rear port they register 270, 230, 235, and 430 degrees From the right front to the rear they register 410,290, 450, and 260 degrees. Anyone know what I should check?