I currently have a TPI 700r4 with non lock up and a Hughes 3000 stall. If I were to run like 3.55 gears on a long cruise at say 2500 rpm in overdrive do you think the converter is slipping much. The tech guy at Hughes told me at light throttle it should not slip much and will be ok. I am a little nervous so I will most likley runs 4.10's cause I want to bring the R's up a little closer to the stall rating. Any thoughts??

There is no distinct correlation between stall speed and cruising rpm's. Smaller, looser converters generate more heat at all rpm's. The higher the gearing, the more the load on the converter when you drive. Your overdrive presents the largest load, about 30% more than drive. If you were to change your rear gears to 4.10's, the load would change 15%. You may find that running in drive with 3.55's is better than swapping to 4.10's and running in OD.
You can see one of the big advantages of having a lockup converter. My 9.5" PI converter stalls at 36-3800 rpm yet will tow a trailer all day at 2000 rpm locked up.

I don't think you'd like 4.10's with the 3.06 1st gear of the 700r4. As it is 1st is over in a hurry with 3.55's. If the trans is capable of lockup you'd be better off to swap the convertor. I'd invest in a trans temp gauge either way.

Well talked to the guys at Hughes today. Either I am going to convert my 700r4 to lock up or drop the stall to 2500 and go with 3.73's. That route would be much cheaper and since I plan to go to a stroker in the future the 2500 would work even better.