Several comments caught my attention, like E bay purchased twenty + yrs ago
The first stroker motor I had was a 1959 383 motor that had a 413 crank in it that had been welded up and offset ground to make the stroke 5/8 longer than stock, I was told it was a 454 C.I..
I didn't have the tools or skill to verify the stroke back then
It had steel plates welded onto the counter weights for balancing also, not bolted on brass weights
Old times, old ways
That exhaust sounded a lot different than other 180 degree crankshaft 4 stroke motor I've heard at the drag races years ago, those where 426 hemi motors raced in modified eliminator in either 1970 or 1971 at the NHRA Winternationals. One car had a set of 180 degree headers and the other one (both where 2nd gen Baracuda) had the 180 degree crankshaft, both cars sounded like they had six cylinder motors in them
Lycoming aircraft makes a flat 8 cylinder opposed air cool aircraft motor that is around 720 C.I. that made 400 HP at or close to 2600 RPM N/A. , I think they have a 180 degree crankshaft in them and they don't sound like a six cylinder motor like those hemi motors did
The thing to remember about a 4 stroke 180 degree crankshaft motor with 8 cylinders is two cylinder will be firing at the same time to get all eight cylinders to make the complete four strokes in 720 degrees of crankshaft revoltion, correct
I know guys that would have killed to get that Chevy motor back in the day