You should see the skull on a fully mature American Bulldog of the Johnson strain. Also the muscle mass. About 125 lbs of pure muscle. The Scott strain of American bulldog looks like a giant pit. They can get up to about 120 also. But a more normal weight for them is in the 80 - 100 range. There is also a third strain of ab known as the hybrid. That is a johnson Scott mix. That is what my pup is. He is 10 months old and weighs 81lbs of pure muscle already. I have seen heads on Johnson Ab's that are honestly as large as a basketball. Most t he size you see in the pits today has been bred in to them. They should really only be about 50 lbs. 70 for a pit is gigantic.
Adoption is GREAT idea parker. Pitbulls are some of the most loyal and stable animals on the planet. If you raise them correctly you will have no more trouble with one than a jack Russell terrier. He or she will adore you. If you want something that is larger look into American bulldogs.
A picture of my pup at 10 months
The problem with a lot of Johnson breeders is that they only breed for size, weight, and shortness of muzzle. I would hate to have a 150 lb blob who couldn't move, couldn't take the Hawaii humidity because of a short muzzle, and was so undershot that he couldn't hold. I have become a big fan of working Alan Scott/Billy Hines strain. Hines, prior to his death, bred for performance, mainly hog hunting. A lot of his dogs, (Von Sanctuarys Loki, his son Bossman, Bossman's daughter Kombat, Hillbilly, Countryboy, Snowbird) were functionally fantastic dogs that could take down a 400 lb Russian boar, and eat at the dinner table with toddlers. I have two bitches, both descendants of Bossman/Snowflake outcrosses who are low slung, thick, agile, have a five inch muzzle with clean reverse scissors bites, but their heads are wide like a shoe box. They can breathe, move freely, have endurance to do high intensity things for 2-3 hours (weight pulling and protection training) and are docile around friend's and family. I also have a 7/8 Johnson Male out of Mark Landers breeding at MGK. He is the only Johnson breeder putting out hard dogs that are physically functional and "look" the part. (Sure Grip isn't selling dogs anymore, Kyle Symmes is into other breeds now like the rat terrier). If I were to get another Scott Dog, Larry Koura puts out some fantastic dogs, as does Steve LeClerc. They both have Masher/Margentina (Painter) line dogs that are fantastic.
I think the AB is the perfect dog. Like having a bigger pit, they don't come with the typical stereotypes that have given Pits a bad name. When my insurance guy calls to renew my homeowners policy, he still asks if I have Bulldogs. If I had a Rott or a Pit, my rates would have been higher. So a few jackasses spoil it for everyone. Like others here, I love all Molosser breeds. I would love a good Tosa Inu, or a Boerbel, or a Presa Canario. The problem is there aren't that many breeders with which I can trust. The ABA has a great list of breeders who breed for functionality over form. Function is always first, looks second.