2001 Chevrolet Suburban oil leak and towing

i was wondering if i want to tow say at max a 6000 lb load about twice a month with my suburban can i i know the capacity of suburbans 1500 is 8000lbs of towing but i have an oil leak and very small tranny leak will this affect my towing ability or highly stress the motor i keep my fluids up and spoil my truck with pennzoil lucas oil and wix products i didnt know if my towing abilty would be affected