Well I reciently had a Jasper class 1 4L60E installed and I've been noticing a few weird things on how the trans reacts. There's usually a delay between shifting into drive or reverse...like it feels like its in neutral then i feel it engage very obviously. also, if im going like 10 MPH and get upto 1600 RPM the trans feels like its almost shuddering cuz it seems like it doesn't want to be at those RPMs, and a little bit of gas and it'll hit into the next gear. keep in mind this trans is pretty heavy-duty for the warranty given. it's so easy for me to let loose of the tires, i just give it some gas and let her shift then all you hear is the tires skidding along.