There are loads of crate engine suppliers out there, literally hundreds. I can get you a 7-800 bhp LS engine on a pallet tomorrow if you want, complete with ECU, loom and mounts. The problem is they aren’t marketed well. People in their particular area of the car scene will know about them. It isn’t worth the manufacturer spending money outside this circle to advertise their engines. The majority of people will buy the SRT and just drive it, at most they will change the wheels. Most modifiers like to build and modify their own engines. These crate engines are for rich guys who have never got their hands dirty in their life. They probably still have a nanny to wipe their poop and wash their clothes at 30 years of age. They just want to throw money at having the fastest car in the village. They see something online, pay for it then pay someone to fit it with no other knowledge than 1,000 bhp y0.
Also a good point made about the blown diffs and trannys. The kind of people who will buy this will be like, wow, 1,000 bhp, and give no consideration to the rest of the drivetrain. I think the phrase is “daddy’s money”. Met a few of these guys here already and I have no time for them but if I know someone is genuinely interested I will talk to them all day. Top gear fans, nuff said.