Hey Guys, a few months ago my diff blew and had to resort to a SC300 4:27 diff into my car. Now after driving for two months i have some issues okay, the acceleration is cool, but its without draw backs. High RPM"s Daily im past 2K going 40! going 70 im past 3K rpm, and my combined is 18 mpg . My question to you guys is would this constant high rpm hurt my engine and transmission more than normal? and if i lift off the gas i get a hard downshift the almost jerks the whole car, i did a drain & refill of the trans fluid and the behavior has stayed the same. Anyone one else running a 4:27 in their SC400?