Another guess the Dyno Numbers

[67autocross]

I just watched a 340 with cleaned up J heads and a true 10.5 compression piston come off the dyno and it made 425hp with some cam that was purchased while Bill Clinton was your president...I don't see any issue building a 30 over 318 with some CNC pro-max heads that would not lay down four and a quarter...

 

[PRH]

In 1990 I built an 8.8:1 360 with cleaned up 2.02 J heads.
Torker II intake, 650DP carb, 1-3/4” headers, 509 cam.
398hp.
Went 12.40’s in my Dads 3960lb 79 Córdoba.

 

[MOPAROFFICIAL]

How Much Horsepower Does a Dodge 360 Engine Have? (reference.com)

Yes he is high.

Maybe fewer accessories than the 'as tested' factory version.