The Performer 289 is basically an aluminum copy of the std, stock 4 bbl factory iron intake, you shouldn't need any unusual acellerator pump settings over stock with it.
That will be the next thing I check. Since it started after I changed intake gaskets - thought it was something related to what I did. I will check accelerator and floats next but since they were okay before gasket change I'm not real hopeful this is it. But checked vaccums, timing and it does not seem to be the probem - running out of things to check. Thanks
First, Any changes you have done will make it nessassary to retune or readjust your base settings.
Start with timing and carb.
most of which have a trial and error testing to get it correct.
Most manuals are just a guideline to get it in the ballpark,
it's up to you to set it to it's best performance because each engine is a little different.
If your timing is set so that you have easy starts and no spark knocking under load, then your flat spot off idle is carb related.
80% of that can be cured from proper setting from float level and A/F mixture with correct accellarator pump settings.
If you have the screw type, start with it approx .010 gap in the lever to screw. more gap will cause a lag inbetween the time you open the thottle blades and when you get the pump to add fuel.
less gap start the fuel to flow quicker and may be just enough to cause a flooding feel to the engine.
Back to trial and error, a small amount to adjustment can make a big differance...so keep trying.
Thanks based on your description timing is good. I was getting hard starts when warm at first - backed off the advance - got around 11 degrees B. I did pull the bowls and checked floats (non adjustable type). When I open up the a/f got a little better - not as pronounced but still there. Happens off idle and when I give it a little push at cruising speed. I do have a bigger squirter for accelerator - just did not think that was it since it was okay prior to gasket change. I'll try tht next and see if any impact. thanks
Put a larger squirter on accelertor - no difference.
Timing is good, does not appear to have vacuum leak anywhere, new fuel pump, lines, filter & carb. Set A/F setting on carb to get highest vacuum. Dropping it off now with someone that is suppose to be good with Fords - we'll see what happens. thanks