Greg I think I may be ready for a new tranny but have some ?'s

[yaeger]

Ok here I go I have a 99 L built LB, KB . putting down about 640 rwhp and 690 rwtq on a stock trans here's the problem. the truck has about 9000 miles on it and I have a PI converter and a art carr VB. The trans is shifting all over. I went racing last weekend and the trans was shifting good 1st to 2nd but 2nd to 3rd it would shift at like 4800 4900 so I called my tuner and he said he has the shifts set a 1 to 2 5400 and 2 to 3 5300rpms. So I sent my chip back to him and he upped the shift points. he said lets see if that helps if not it may be in the trans. I went out this weekend and the first run shifted crazy.1st to second shifted at like almost 6000 and second to third was above 5000. the second and third run started to get worse after the shifts the truck started to like surge not quite bog. It was kind of like after the shifts the truck would falls on its face and get up and fall again then finally go but that only happens after shifts. Do you think this has something to do with the trans or something else.

 

[Sick03L]

Sounds like it in you're tune as far as the shift points go. The surging could be the convertor locking and unlocking. You really need to get it tuned with a Tuner present so you can make adjustments untill it correct.
Now I will state the obvious.....You need a built trans. You built everything else now, put in a MB/TD!!