SBC engine number ID

[Dave]

First ever MoT time coming up this week so at the weekend I checked the engine number on the supposedly 350 in my F100. I then thought I'd check to see what the number relates to and this is where I got conflicting information.
From the 8 character/number sequence I've confirmed the following:
Ist character - it's a Flint engine
Next 4 digits - give me the day & month of manufacture
The last 3 characters are causing me a problem though:
0MJ
Anyone any ideas?
Dave

[Adam]

Dave, could that possibly be CMJ ?
CMJ is a police engine code.
If it's a 350 it is from a 1974 full size car like a Caprice or Malibu.
If it's a 305 then it is a 1980 Camaro.
Does your engine date match up with either of these?

[Dave]

Adam,
I think you're right and it is CMJ. If I.m reading things right all the date codes tell me are the day and month, not the year.
Dave

[Adam]

Yes dave that just gives yoiu the day & month the engine went together.

Small block casting date is on the drivers side of the block at the rear on a flange in front of the bellhousing. The letter is the month.

A = Jan, B = Feb, C = Mar, D = Apr, E = May, F = Jun, G = July, H = Aug, I = Sep, J = Oct, K = Nov, L = Dec
Next 2 numbers are the day (as per the way the yanks write the date)
The last number is the decade. It's up to you to work out which decade which having the car is easy. Not so easy when you have just an engine!

If it's a 305 between the core plugs on the side there may be a 'H'.

Take a valve cover off and post that number up. The last 3 are the important ones. Chevy generally used different heads on the 305 & 350 due to bore size so you should be able to tell that way too.

[Dave]

I'm still trying to identify my engine. The casting number on the block is 3970010.
Any ideas?
Dave

[DeuceTudor]

http://www.73-87.com/chevy_ids/blockid.htm From this link using your casting number ,shows its a 327 (1968) or a 350 from 1969 - 79 ,2 or 4 bolt mains fitted to car,truck or vette. take the left side rocker cover off for the head number that may help with matching up engine size and year .hope that helps .

[Adam]

Dave
The 010 casting is one of the most common. Its a 4" bore block. The size is crank depenedent but more than likely you have a 350 in there mate although as stated it could be a 327 or 302 as they shared the same bore. The only way to tell if it's a 2 or 4 bolt is to pull the sump and look.

That CMJ you have on the side possibly means it's a police spec 350 but whats inside doesn't always correspond with what was cast into the block. If it's an 010 block it's definately not a 305 thats for sure!