Glenn,,, your numbers are very close to what I came up with doing the same thing just never thought about posting them. Great idea,,,, I'm now looking at the cost to do a 5.3 LS motor for the build instead of the 383. Seems you can get good HP from the LS series without having to do a lot to the engine. These engines seem to run like a sowing machine from the factory and are super smooth from idle to red line. The lower end is good for up to 600 HP as it is from all I've read. There's a UTI grad at a local shop near the house who tunes them and he claims getting the 400 HP I'm wanting is very easy in a 5.3 or 6.0. The plan would be to get a donor and bore it to a 5.7 and go from there. Once I have all the info the decision will be made.

I'm like most on here,,, I prefer to know what's in my motors and how they went together VS getting one built elsewhere. This is not saying assembly line built motors aren't any good,,, always check the reviews,,,