I installed an Edelbrock QS carb about 800 miles ago. I was not sure what angle to install it, so I made it so the bottom of the bowl was level when the bike was off the kick stand and standing straight. I recently purchased a Clark 4.3 tank, excellent quality I might add. When removing the stock tank I noticed that it had a small wear mark in the plastic where the corner of the top of the carb had almost worn a hole thru the tank. It had come very, very close to making a hole in the tank near the exhaust header. This possible hole in the tank would never have been visible without me taking the tank off. All it took was a simple twist of the carb to relieve some of the pressure that it was creating on the tank. Just a heads-up to those using the stock tank with the QS. It is possible that it could create a fuel leak if installed so that it comes in contact with the tank. The Clark tank however has plenty of room so that the carb does not come in contact with the tank. Ride on!