No shift under load

[scarface_x360]

Hey guys. I've got a stock tranny that has been rebuilt with a shift kit installed. It worked fine for the first couple years i had the car. Two years ago the engine was rebuilt and we made a few mods such as a roller rocker cam. From what i have done i should be capable of a low low twelve.
My problem is that when i get on the throttle, it does not want to shift. It will rev itself out and i have to back off the throttle to get it to shift. The fluid is very clean and doesn't smell burnt at all. I have had it serviced recently as well so it has a new filter and whatnot. If i baby the throttle it shifts soft, which is abnormal as well because with the shift kit it would slam into gear.

Any suggestions? If I'll be looking at getting a new tranny, what is recommended? I drive the car on weekends usually, and want to run 11's before long. Also i want something that would shift very hard.

Thanks guys

 

[chris718]

sounds like there is low mainline pressure.installing a pressure gauge qill verify this.if your in the market for a trans we offer a stage 1 for your application that comes standard with e4340 shaft forward drum ,http://www.ckperformance.com/resources/GM2004RTRANSMISSIONS.html