C3 Motor ID

[Marc Wilborn]

Hello

I owned a 1968 vert 435 car along time ago and was the second owner. Original motor was long gone so I bought a 321 4 bolt main block to go in it. I eventually sold the car but kept the block. The date is difficult to read but the front pad has T1110ID stamped in it. Rest of pad is clean with broach marks. Any help where the block was used for? Thanks Marc

[Henry J.]

Re: C3 Motor ID

Marc:

Alan Colvin's book shows the "ID" suffix as applicable to 1968 passenger cars (not Corvette) with 425 HP.

[Marc Wilborn]

Re: C3 Motor ID

Does anyone know when 321 blocks were forged? The date code has an H I think but the 7 is very obscured by wear. It has two sleeves I believe and I would like to get rid of it. This is not an attempt to sell but merely to figure out what I have so I do not mislead someone. Thanks

[Joe L.]

Re: C3 Motor ID

Marc-----

The blocks were not forged. They are CAST of gray iron. Anyway, the GM #3916321 block was manufactured between ABOUT July, 1967 through ABOUT January, 1968. It was used for both passenger cars and Corvettes during that period. Your date fits right in the period.

[Henry J.]

Re: C3 Motor ID

Marc:

The limited information I have on 321 block casting dates supports what Joe Lucia indicates.

The earliest 321 block in my database was cast on August 18, 1967 and the latest one was cast on December 27, 1967.

The latest example in my database of a Corvette, originally fitted with a 321 block, has a trim tag date of February 21, 1968. Unfortunately, I don't know the casting date of the block in that car.