There is a kit available that replaces the output shaft on the th350 and provides a spacer to make up the distance between the 350 and 208. I'm running this on one of mine now. I got the kit from bulkparts.com I've also seen the adapter kit available on ebay, but the price has been higher on ebay. The bulkparts kit is around 100 I think. If you want to junkyard it, you have to find a spacer and output shaft from a th350/np208 combo or have a shaft made from a 2wd one. My daily driver has a 700r4 that I just had rebuilt with the performance kit and shift kit from bulkparts, and it shifts as firm as the th350. Now I'll just have to see if it lasts as long.