I have a 2004 Silverado 1500 5.3L with a 4L80e swap. Everything is bone stock except a new torque convertor with 1600-2000 stall. With the 4L60e, the 1-2 was always uncomfortably firm, but I thought that was just a characteristic of it. After finishing my 4L80e swap, it's doing the exact same thing. Every other shift is good except the 1-2 which jolts your head. There are no codes. Is this normal for GM 4 speed autos? I tested bringing the 1-2 upshift pressure down by 5 percent which actually made it a lot better. This is my first big project and I'd appreciate hearing some pointers. Thank you