I have a 68 ss396, i know the engine is not original, supposed to be a 66 396

The only numbers I find on the motor are in the front passenger side (behind alternator)

They are (I think)

T042IIar

and

61207643

Can anyone decipher these for me.

I looked along each side of the motor and was able to look at the rear of the engine on the passenger side, have not been able to get my mirror back on the drivers side. Did not find any numbers or codes.

The motor had a canister type oil filter.

Thanks for your help

T=Tonawanda engine plant
0421=April 21st engine assembly date
IAR= 66 Impala 396/325hp MT L-35 Rochester carb

Partial vin
6=1966
1=Oshawa assembly plant
207643=sequence number

Edit: The casting date for a 66 should be on passenger rt. "side" of engine by the freeze plug. Letter for month and number for day and last digit of year.

Rene
66_Malibu