Am a fan of Ford c, w's, and fe's big blocks or small blocks, but what are your plans for this truck? If you do swap the 351c in an want still use toyota t-cases am sure something will break, with alot more torque and hp going through.
Also I dont think a t-18 can be bolted up to a toyota t-case? Maybe a divorced adapter? Sure you could bling the t-case up but i dont still think it cant handle that power. Just use a ford t-case from a 70s 4wd truck.
Axles might last a little while depending on your foot lol. Am sure upgrades needed as well, and I agree with H8PVMNT. I've seen the bling toyotas with all the top offroad gear from marlin, tg, etc, get blown away from an orginal most compele truck with a basic lift or no lift do better. Not sure why, maybe driver lol. Same goes for those formula toyotas, either they baby them or something i wont say lol. And again the basic toyota beats them too.
Heck look at the toyota 1st gen, but maybe some upgrades here and there but mostly toy running gear at king of the hammers 2012, the black one. That truck did better than most of the high dollar machines. still if your heart one it, get some running gear out of a 70s ford truck or out of early early bronco.
Plans for the truck is off road only(Trail riding, rock crawling and some deep snow runs while i'm out in Colorado this winter). Now I do do more trail riding with steep hills alot more than I crawl but I still wanna be able to crawl when I need to or want to. The only reason I wanted to keep the yota cases was because I just bought a dual transfer case adapter and was gonna run duals, but I can sell that no problem. I already have the 351C, T-18 and either a np205 or np203 I don't remember which one's in the truck that the motor and transmission is still in. If I really do end up doing this swap I will more than likely put a set of 1 tons under it. Don't really see the point in sinking alot of money into a set of Yota's and have to baby them because of the power and running between 37"-40" tires. I'm sure they would last awhile but i'm not afraid to hold one to the floor when need be. I'm not trying to sink alot of money into this truck either.
The 22R that is in it needs to be rebuilt anyway, it smokes like a damn freight train. I know the 351C is alot bigger size wise than a 302 or a 351W but stock them have around 250ish hp when the cleveland has 330 stock and more torque. I've just seen it to many times at some of the places me and some of my other buddies ride at where they can wind their yotas and samrurai's out and just not be able to get enough wheel speed to get up some of the slick muddy hills. For instance we had 3 samurai's 2 toyota's and 1 cj5 trying to climb this pretty steep hill, had alot of roots and rocks sticking out of it also not to mention it was slick. All of the samurai's and yota's had to be winched up it. The cj5 with a mild built 304 stock lift with 33" boggers went right up it no problem because he had the power to provide the wheel speed needed. Just seems all the jeeps and v8 powered bronco 2's that I ride with are about to go more places because of the wheel speed. And I can't stand when a Jeep out does me.