Use a Nissan V8 or a Toyota V8. Any engine with the cam in the block is a giant leap backwards in technology over an L. Yes it will be more work, but then you will be unique, unlike the other two people that put SBCs in this chassis.
Nissan TB48, 4.8 liters of inline 6 fury. Too bad its impossibly large.
Or just stick with your L24 and get a L26 rotating assembly and turbo it.
You are talking about more power when you are still running stock fuel injection, so I am not sure what you think your gaining without replacing that first, or course if your heart is set on a v8 instead of an inline 6 then thats useless to you anyway.