I ran 38 lbers and a stock convertor for quite awhile with no problems. When my tranny took a dump I went with a shertz hi-pro tranny. Since the tranny was out of the car I went with the Pro-Tech 3000 15 and 1/2 convertor. Changed to 57 lbers when they came out just for safety.
I would say that 42's and 3000 is fine,but someone probably has a different opinion. With more technicals at their disposal.