Well after a lot of reading, study and thinking I've decided to pour more CLR in there and leave it for at least a week and maybe two. It did after all break down a lot of the crud and that was in 2 days. Possibly I was too quick to drain it. Maybe in 10 days it will finish the stuff off completely. All other acids I looked into had pretty sincere warnings and the strong vinegar (which worked very well at first) lost potency pretty quickly and then seemed to not be doing much. I'll let you know how it goes. Thanks for everyone's help.
Jon

~ Jon
1952 1/2 ton with 1959 235 | T5 with 3.07 rear end