Yes it is. For sure it has some stout camshafts, compression and many hours at the tig and porting bench. Looks like they are running 3 holley 4500 series carbs. Thats a lot of air going through that motor.
I bet the thing hit at least 8000 rpm.
51 GMC 4.2 turbo Can't solved today's problems using the same technology/thinking that created them