I bought Precision of New Hamptons Billet, 3800rpm stall converter with the 3 carbon-fiber disc lock-up clutch upgrade. If memory serves is was near the $1k price point. You stall will depend on the information you provide about your combo to them. I recommend asking for Milt. He was very helpful.
Once your transmission is mated to your motor, be sure to measure and verify the front-to-rear clearance or free play that the converter has between being pushed all the way into the transmission and pried forward. There is a critical clearance spec that eludes me as of this writing.
