[caddor38]

Originally Posted by FASTASSBIRD

The problem I have is that people are fighting over this block being the holy grail, an “HO” motor

There is no fight. It isn’t the “holy grail” of HO motors. That belongs to the WC hands down. Don’t believe me just try and buy one. Expect to spend 4K and up I would guess.

My gut reaction to the whole thing is that it was an extra they had sitting there so they stamped it YC and moved it out. I’d like to see the part number on the front main cap that will say a lot but I can already see something else on the pics that does lead me to think it was a legit original 4 bolt main block. Not uncommon for them to need a block and use the first thing that they could grab. Being a vin in the 4k’s (basing this on previous mentioned big cars starting at 300k.) would mean it was very early in the 71 year.

Thanks for providing the info on the Vin. I thought the number was high with 7 digits, so can i assume this was the 4,555th car built in the 3,000 series in Pontiac Michigan. However, the motor began as a HO block since it was given a 4 bolt main. However since it was probably detuned to the 8.2 compression 325HP version folks are saying its non-HO and there are many sites calling the detuned vs an HO motor and some sites dont. My contention is that once they created the block in 1970, with a 4 bolt main and stamped it 484677, the block was then a 455HO according to my info.