I am using this antenna, installed on a 2007 F150 using this mount, all installed it looks like this, running this coax cable that I was told from another user was too long so I trimmed it to 9ft, routed over the brake booster through the firewall grommet and up the dash (no kinks or loops), attached to this SWR meter, hooked up to this radio. I've been following this guide for installation and troubleshooting. I have good power to the radio (turns on and makes all the usual noises), set the squelch to just past the threshold of static noise, I've verified ground continuity from the bracket to the vehicle chassis (0.6 Ohms), as well as antenna continuity (0.6 Ohms), and ground and hot continuity of the coax (0.6 Ohm for both). I think that's everything.
As far as I can tell, I have good ground, all connections are secure, the SWR adjusts accordingly when I turn the dial. What was once a super long cable potentially causing interference is no longer an issue since it's a straight run now. I haven't done a radio check yet, but after the adjusted cable length I'm now getting SWR readings above 3 (CH1 @ 3.2(ish), CH40 @ 3.5(ish)), so my SWR readings are now more even. But now I'm unsure how to get the readings down.
E: SWR is now in the 2 range after finding out my hood was interfering. Sitting at 2.5 and 2.2 for CH1 and CH40 respectively. Would a spring get this down to nominal?