Edelbrock Pro Flo 4 EFI

What is your vacuum reading at idle?? I have the ProFlo3 on my 408 with a 110* cam and 10” of vacuum at idle and have no issues tuning. I have the same issue trying to set timing and have found It is easiest to set by bringing the rpm up to about 2K with the timing locked at 12*.

To much timing to early will cause erratic behavior around 3K rpm. I have increased the rpm for all in to 3800.