***WARNING Crazy Long Post*** This is a summary thread about my 72 Skylark 350 and its TH350/200R4 trans swap. My experiences and learnings for what they are worth. This is not a by the numbers How-To, but a summary of sources and tips I think valuable for those attempting the swap. Enjoy. My goal was cruiseable hiway RPMS with my 3.42 posi rear, in a stout transmission that could handle my mildly built Buick 350 and whatever thrashing I might throw at it. I wanted to achieve this in a low-buck manner as well. Consult www.turbobuick.com or www.CKperformance.com to determine which 200R4 core is right for you. There are a lot of versions of this trans, each with its own characteristics. Some are better suited to performance than others. I started with a 200R4 out of an 86 Olds Cutlass, because it was found local. I paid $150ish. OG valve body (low performance…ugh) for the 307 V8. Sources of information and parts: www.CKperformance.com – I bought their rebuild manual, VERY informative and worth every penny. I also used their #24RSRK/A shift recalibration kit with excellent results. An excellent resource for all things 200R4. www.PATC.com – I bought speedometer gears here that suited my 3.42 posi rear. Their site makes gear selection a no brainer. www.turboBuick.com – The Turbo Buick guys know all about the 200R4 trannys and there are a lot of deals on parts to be had there. Great resource for information and parts. I scored a Superior Oversize Intermediate Servo there, as well as a D5 torque converter from a Grand National and a Used Hurst QuarterStick shifter. www.transmissionpartsusa.com – These guys have about anything for about any auto trans. I bought several odds and ends here, including a Hardened stator support, Trans assembly goo and some pump upgrades.