GP's really don't need a line lock unless you're running 10's. I'm not sure what stall his converter is, but I"m guessing around 3k. Not sure on the gears either. Good luck trying to launch an auto at 4k.. especially a GP. You'd need a 3800 stall or so to do that.
He might just need some more seat time in the car. Kilkare isn't the best setup for FWD cars.