Hello XXXXXXXXXXXX,
I have a pretty good bit of experience at the drag strip over the years. Maybe I can help you sort out some of your problems...First thing I learned over the years in 1/4 mile drag racing is this. "Never Make More Than One Change at a Time".
You have indicated that you were running a lean setup with 18 degrees of advance, then you richened things up with the new fuel pumps and bumped the timing up to 30 degrees?
I need to have you clarify if you made the fuel pump changes and timing changes at the same time?
What about 60 foot times? Did they go away too?
ET is one thing, but more important to me at the moment, is what did the MPH do? Is Mile Per Hour still where it was, or did it drop off after the fuel pumps changes?
Why MPH......This will be an important point to monitor, due to the fact that you are appearantly running a Glide and a Converter. With the horsepower you are running, the converter can begin to go away, and you can play heck finding that as a problem.
You indicate that things now smell rich. If they smell rich, they most likely are. IF you are too fat on the fuel, the spark plugs may or may not color for you. You Can't read them.
LEAN makes horsepower. Begin to take fuel away a little at a time until your performance starts to return. Read the one Spark Plug from each bank after every pass. (minimum) Reading more is better.
Make sure you don't go too lean too fast, or you'll pay for that mistake.
Have a Great Time at the Strip and I hope my input has helped. I'd love to see your car sometime. Please let me know if I have helped in any way. Thanks
GM-Frank
ASE Master Certified
37 Years Automotive Diagnosis and Repair. 25 Years of General Motors Dealer Experience