Gergo, My XK 150 has 2 HD6 Carbs (1 3/4"), although admittedly it's way undercarbed. It's a 3.8L with some hopped up cams. Are you upgrading to HD8's or do you have a triple HD8 setup currently? I've been toying with the idea of upgrading to HD8's. Jonas Payne PBR Consulting 702-882-6711