how to determine original engine?

[Rooster's 67]

I am wondering if there is a way to find out the original engine of a '66 i just picked up?

truck came no motor or trans, was original three on da tree, and has small block motor stands in it, the spid tag is missing and no build sheets present under seat

vin isC1446S136139
i have figured the model number is C1434

is there any equipment to look for that will help determine V8 as opposed to an I6

wish it had a tach dash, could pull it and see if it had V8 or I6 tach...lol


now to decide, Big block or LS series motor? Hmmmmm