The d44 will hold up no doubt but it may take a little work to make it bullet proof. I mudraced an 86 250 with race cut 44 inch boggers and a 3/4 ton hp d44 and it held up behind a built 351w for a while stock. The second season I raced it I busted a short shaft so I replaced everything with warn chromoly shafts, warn hubs, ctm racing joints, and 4.88 gears it was a beast after that and ran it for 2 more years without any problems til the truck got stole.