Weird 2-3 shifting

[keystoneGerm]

Ok, I searched for a when and can't find a good answer. I don't know what keywords to search for. I am looking for a little help.

I just rebuilt my TH350c with a transtec level 2 kit. All bushings were replaced. I had no shifting problems prior. I also installed the superior shift technologies shift improver kit. I followed all the instruction to a t. This is the kit instructions.



So when I am driving and at a light load the transmission shifts between 2-3, and kinda searches or floats between them. If I give it more gas it is fine, or I am going a little faster it is fine. I am ASE master certified, but truly don't remember alot of the automatic transmission components function.

If I were to check line pressure, I am worried that it would t be accurate because the kit had me block off the intermediate accumulator like in step 12. What do you guys think?