Hey guys, I asked back in the fall for suggestions on replacing the headers on my drag car. The most popular choice was super comps 1.75 primary so I bought some and installed in place of my cheap 1 5/8 headers. My combo is a 408 11 to 1, j heads with good porting, 560 lift solid cam, victor intake with 830 holley. I was alittle afraid that I did not have enough cam to make the bigger headers work well. Well I did not loose any bottom end and picked up about a .5 mph on the big end. It ran a 8.69 in the 1000ft on a cold track, almost on new record for this car on the first run. After one run I backed the throttle off to about 3/4 because my 17 son raced it this weekend, so I did not get to fully test it out. Hell it still ran 9.04 at 108 in the 1000ft. Strange thing that I noticed, the exhaust was quieter at idle and at full throttle. It has the same single chamber flows that it had before the header swap. Thanks for the advise. Oh the install went fairly well. My engine was on a motor plate and I had to move it 3/4" to the pass side. I guess it wasnt in the factory location to begin with. After moving the motor they fit great.