I'm in the process of installing a G body front clip on a 51' Chevy truck. I've got the truck frame level front to back and side to side. I've got the front wheel centerlines scribed on the floor and both the truck frame and clip have been cut and ready to put together. My question is what do you level off of when installing the clip, front to rear. The side to side is no problem, but I want to make sure both sides are on the same level plane and that it does not have any twist in it before I start welding it. I have read several posts on this subject and I do remember one that said to level the lower A frames. I cannot see a good flat place to set the level on the lower A frame, even reading the level from the bottom of it.