Modern stock 6 cylinder HP  

They ranged 275 to 300.  250 Chevy straight six. A 190 cid Chevy head increased the compression. A cheap header and you had what you had.  Stock ignition with a coil  

Bernie Bailey had a good Charlie Weston engine.  Charlie took a four barrell Holley  and machined it down to a single barrel carb. A real work of art that was legal by rules but the track banned it. Donnie Chambers used a stock type clutch by the rules but it was stock in a Honda.  That got him a one year suspension.  Back than anything cheated got you a one year suspension. No messing around.