Noticed a couple weeks ago my RPMs were about 300 higher than normal during my 30 mile commute to work.Thought I felt slight shudder next day at around 65 MPH. All original 3.8L and 4L60E with 98K miles. Received P1870 code next day. Stopped driving it, drained fluid (which was at proper level), checked TCC solenoid for proper resistance (not shorted, 10.49 ohms).So, yes, probably TCC regulator valve bore wear. I've never removed a valve body, looks doable, but car will be on jack stands with me on my back. Looked into the Transgo TCC reg valve, Teckpak Fitzall valve, and Sonnax TCC reg valve. Sonnax's site warns of damage to drivetrain if PWM valve is replaced with on/off valve, which is what the Fitzall valve is and I believe the Transgo valve as well. Leaning towards Sonnax, are these my options? A) Remove VB, buy Sonnax valve and reamer, gaskets and possibly separator plate, take to Trans shop for reaming. B) Found Shift Rite remanufactured VB on Amazon for $250, which has already been reamed and has Sonnax valve installed, includes upper and lower gaskets and separator plate (also includes trans filter and pan gasket, but I already have AC-Delco filter and gasket). Suggestions/recommendations? Need advice.

Here's the link to the Shift Rite VB
Thanks in advance, Philip