I have a set of 4.57s set up on a spool in a 489 case if you're interested.
Don't know what cam you have but more converter would help a ton off the line. My converter flashed 5200 behind the 408 and I drove it a bunch with no issues.
You can shoot me a PM for what you want for that case. My converter is tight, 3200, but when I assembled the car it was intended for street use only. Since it will always remain a street car I doubt I would go looser then 4-4500 stall. Motor has all the TQ in by 4500rpm.
