IMSA GTU vintage racer build in S30 Series - 240z, 260z, 280z Posted 19 hours ago · Edited 18 hours ago by clarkspeed First up I needed to revise the front end. The car was originally designed with a V8 in mind and had a cross member designed to hold one. I know that I will be eventually running a L6, so after a lot of thought, I decided to run the standard Z car cross-member. This would save some time and I knew with a little modification it could be used for most of the things I want to do. It also allowed me to set the standard Z car front suspension pickup points without too much trouble. But it was still not easy. I had to also relocate the 2x2 square tubing to mimic the Z car frame rails. So essentially the bottom of the 2x2 channel is located in the same location as the stock frame rails, (note this is a critical measuring datum, I will discuss later). To accomplish I had to level the entire tub, which was welded down to a 0.100” steel plate sitting on the shop floor. I used strings tied to the chassis points outlined in the shop manual. I don’t have any early photos of setting it up but you can see the final result in these 2 pictures. I was not really happy with the way the 2x2s tied in with the 2x4 square coming out of the tub. To get the correct height, they ended up sitting right on top and I really didn’t want to tear into the 2x4’s or relocate those. It just seems like a frontal impact would drive that front clip right into my lap. I added a 2x2 brace and a doubler plate to the weld joint. I still plan to add a crush zone in front of the radiator in the future. You can also see the 2 square tubing rails that are tac welded and located at floor depth and width of the rear measure point located behind the seats. Next I will post about the strut towers and control arm pick up points.