I have a 69 camaro I drag race. It has 7730 computer. My trouble is that at the beginning of this year I put the combination in the car and have ran it at the drag strip. This combination has worked before. Now I make a pass and it runs good. Just say 7.60 1/8 mile. Next pass will be close like 7.598 or 7.609 then the third pass will be a 7.71. The next pass will be a 7.58. This has been happening all year. I found a fried module in the dist. I replaced the pickup and the module with autozone parts. It ran back to back numbers the next time out. Great Its fixed. Wrong. The second time out it goes to doing the same thing. Got to looking and the timing was not coming off of base at all. Checked base timing and touched the throttle while tan wire was unplugged. Motor died. Unplugged all Msd and put back on GM ignition. Motor ran and did not die. Plugged tan wire back in and timing would not advance. Fried module. Replaced with new holley module. Car ran good and backed up et numbers for about four passes. Then the ET's started moving around again. Checked module and it is good. Timing is advancing with computer hooked up. I take the car out now and it will make a pass at say 7.70, then it will go 7.62, then 7.71 then 7.66. ANY HELP PLEASE. I have been told by my chip maker that GM has had problems with the distributors. Something about the magnet and the reluctor touching at the pickup coil. He said to change distributors.