Darton sleeves won't help as to survivability on this block. I've already said why. You could run all the big name parts you want and then the block will become the weakest link. Sonny Bryant, Oliver, Wiseco custom rotating assy will not save it as far as the original topic. Hardblok and a partial fill might help it last a little longer.
I'd talk to quite a few engine builders to get different points of view and feedback....even if you hear what you don't want to hear.
Really? No problem with opposing viewpoints here, but i really thought that with proper top support for the cylinders 1000 wouldn't be unrealistic. Guess i'm overestimating cast aluminum, though personally I won't completely throw the idea out until I've seen someone try and fail.
oh, & Hazim- the MT-82 is basically the same as in the 5.0s. It's not terribly reliable above the 600-700 horsepower mark. Built MT-82's and Tremec swaps are an option. Our rear end is basically the same as the 5.0s and can handle the same sort of abuse. 1000 starts pushing it, but the 8.8 can hold up. Realistically you end up doing a lot of the same work you'd have to to with a different platform in terms of drivetrain/chassis/suspension. Honestly outside of the engine compartment there aren't many differences between a 3.7 and a 5.0