My converters when I ran my 727 were 5800 and 6200 stall. Not going to pick up the 10+ mph you’re lacking though. Would have been interesting if it were dynoed.

264-272 at .050" 108 LSA .750" lift at retainer is what I’m running for a cam which is smallish in the W8/9 circles. 4.56 gear 29.5x10.5 tire. Been a really reliable set up. Dynoed 773 @7200.