Have tractor rear tires filled with liquid to lower center-of-gravity on slopes. Ponder selection of R1/ag/barred or R4/industrial tires carefully. How many acres of land do you have? Consider a Kubota
L2501 as well as lighter Kubotas. Weight equals stability:
B2301/1,566 pounds,
B2601/1,632 pounds,
L2501/2,623 pounds (all bare tractor). Not that much difference in price. You should be able to do septic install and repairs with FEL bucket equipped with a Tooth Bar and save yourself $6,500. DIGGING WITH FEL BUCKET/TBN ARCHIVE:
Google tractor fel digging - YouTube No HST nor engine problems on slopes, so long as tractor remains on its wheels. Contemporary diesel, HST, 4-WD tractors are hugely better than tractors of 20-25 years ago.