I have owned 3 worked on 15? and in the end the engine I was the hapiest with was a run of the mill 302 from stock parts except eddelbrock heads and manifold, about 300 rwhp with a 411? rear end. It was as fast as any other cobra zero to 60 and never once had any concerns about hurting the engine. It cost about $5k, compared to 14K for some of the name brand engines which I always feared about breaking. Last I heard that little 302 had about 35Kmiles and starting to use
oil. The one I was least happy was a 460 ford, what a dog, reved slow but had tons of torque.
In the end it will depend on how mechanically inclined you are, something tells me big blocks require more attention if you have a solid cam etc. You go to radical and parts wear out alot faster.
These cars are junk. I broke down for the first time the other day. The terminal did not come off the coil the wire did not pull out of the terminal, the f^&king terminal broke in half!!!!