Beginner Road Track Racing: Feedback on Engine Options Wanted

30 year SCCA racer... my class was GT-4 / also GT-lite . not a Mopar unfortunately but a full tube framed 200SX.
My most fun was when I had a street based motor in a race chassis, it took very little maintenance , ran on pump gas and I got tons of track time.
The biggest enemy of a racer is seat time, if you cant go fast with 100 hp on a road course 600 wont do you any good. you have to learn to drive and practice.
Track time and tires are expensive , spend your first money on a good chassis (full cage) and big brakes , I recommend an FIA homologated fuel cell and it may be required by some sanctioning bodies.

contact me by message I'll be more than happy to give you directions
1721661216264.jpeg