Other than the block VIN derivative stamp, are there any other numbers on the block , heads , and intake that show the year?

 

Contrary to internet myth, the large number next to the distributor is NOT an indication of calendar year of the block. It is a mold number and is loosely correlated to year of production, but not always. I have too many examples where it is not. The VIN derivative stamp is the only way.

 

What about the heads and intake, do they show the year?

 

4A heads were used for all three years. Same with the intake. Unless you have something one-year-only like the 1977 Toronado MISAR ignition system, there's no way to tell except the VIN derivative stamp.

 

To be honest, I'm not sure why this matters so much to you. The specs on the 403 were pretty much unchanged for all three years of production. 4A heads, same intake, same 562299 cam, same 185 HP net.

 

Thanks Joe, appreciate the help. I may get a 403 motor, and I'm seeing a 1979 403 long block near me. Do you know of any issues with a latter year block vs. 1977? I'm sure in theory they're all the same, but if you know of any "better" years let me know.

 

I'd imaging this is a 228 Julian date. Why did they make the 8 smaller with the underline? ... unless this was std practice on all of these to stop ambiguity. This particular number would not make sense upside down.

 

All of the other blocks I've been looking at don't have a small third number. I just want to make sure that this date is 228 and not something else...just puzzled on why the change. This block is a 1979 block, the others with full size digits are 1977 blocks, so that could be a change that GM made. I want to find a period correct Julian Date , and also don't know how many weeks/months ahead would be considered a reasonable period. My prod date of the vehicle is 03/04, which is Julian 63.