Stock 904/318 combo had two converts, a low stall and a high stall. Difference between the two of them about 3-400 rpm. Low stall typically around 1600 to 1700. From the photo, the converter you're showing is NOT an original converter, but a rebuilt. The factory does not paint converters. I don't know what it's like down South, but when I worked in the industry, two Mopar converters that were always CORE IN FIRST, HEMI'S AND 340'S.
Contact a builder of high stalls, give them all the information on your engine build and what you've put into it, rear axle ratio, tire size and what you will be mainly using your car for. This is the only way you'll get the converter that is best for your needs. Check with a number of these companies not just one to get their recommendations.
Remember, Summit, Jegs, etc. do not build converters. They buy them from a wide variety of converter builders, and at times they buy based on price. I'm not knocking these companies, but they may lack the knowledge to get you the converter for your application
At all costs, avoid used converters, as you never know of what they look like internally without cutting them open.