i need a little help guys. I am getting knock only in overdrive around 42 mph. I dont get any at full throttle or part throttle. Only when I am cruising around 42 mph. Any addvise would be great. I am tuning with hpt.

 

That is a little bit bizzare. I would start looking for something rattling or resonating. To be confined to such a specific condition like that is what makes it strange. Even if timing were advanced so much that was the cause of the KR, it should not matter what gear you are in or how fast you are going, it's a function of load (MAP) and RPM, and to some extent Throttle position so "closed throttle" or "open throttle" table is referenced.
Is there something else happening at 42mph? Maybe the torque converter is locking up perhaps?
If you have the ability to log data, find out what MAP and RPM it is happening at and try to reproduce it in third or second, perhaps with the parking brake engaged for just a moment to recreate the right amount of load.

 

In OD, TC locked you're lugging the engine. I had a similar issue. Moved TC lock up to 55mph, and had it tuned out on the dyno.

 

have you tuned your ve table? the lower rpm/higher map areas... when you go into overdirve and give her a little gas, as mentioned above lugging occurs, but it hasn't kicked in pe yet nor should it probably. maybe some tweaking in the lower rpm/higher map areas or just a simle lock up speed adjustment as trever has eluded to. check all things jims mentioned as well. since you are tuning with hpt, give us some insight on the things you have changed already or post up your tune and/or scans.

 

Thanks for the help guys. I moved the torque converter up to 50 and the knock is gone. I am going to try this and see how it goes.