Chevy R07 NASCAR engine, 397 cubic inches (6500 cc), 960 bhp for just north of $20 000.
https://www.holley.com/blog/post/get...et_r07_engine/
As far as a Chev V8 engine being used as a stressed member and the problems of dry sumping the Chev engine c.f. Lola T332 all in at 665 kg
https://en.wikipedia.org/wiki/Lola_T332