Question about the 1966 L-72

[Day2_69Z]

Good stuff guys,,, real good.

The engine I have to list is what I feel is a 66 Chevelle 427 High Performance that came from the estate sale at
Smokey Yunick's Best Dam Garage in Town Auction sale in 2001 .
Pad stamp: TO215IK /small pad Stamped 'H Y'
Block Casting: 3869942
Date: need to remove excess paint.... will post.
Vin: 6K16201 ?
Heads: 3873858 Hi Perf X. B 3 6 'H YUNICK'
Alt: 1100696 42A. 6L8
Starter :
Pulleys:
Carb: (2). 3885067 EE
LIST 3246. 022 Date.
& LIST 4781 - 3 2559. Date
Intake Manifold is the 'Mystery' 299 stamped
'H YUNICK' 3878299. Casting Date. 9-27-65
Also has an Original Chevelle Cowl Plenum A/C
with a Reproduction Cowl plenum to firewall.

Could this Be a 450 Horse or 425 Horse L72 ?
There was/is speculation to being an L88 recieved from Chevrolet for Deveopment by Smokey on this Engine. . . ..will pull the Pan to verify any Internals Casting #'s and or Part #'s.