Date codes vs production date for 1972 455HO 4-spd
 

I have a question about how well dates should match up on a fairly rare production car. In this case, the car is a 455HO 4-spd A-body. I bought the car minus drivetrain. Over the years, I've put together a complete motor (minus distributor) from a variety of different sources. The problem is the dates are mostly earlier than the car. I know dates on low volume cars may be wider than a higher volume production vehicle, but I'd like some input on where my dates are too far off.

Second question: If I have a WM block and a couple of SR 455 4-bolt blocks with a late 1972 and 1973 cast dates. I have a H242, a K091, a L212, and a B093. Which block would you use?

My car was shipped on 4/5/1972. I don't have the cowl wall date handy, but I will check. What date range would you expect on the following parts:

- WM block
- 7042273 carb
- 7F6 heads
- 1108436 starter
- exhaust manifolds
- M22 transmission
- 12-bolt 3.55 open rear end

Might matter on which plant built it.
No input on '72s.

It was built in Pontiac, Michigan.

C'mon guys. I am going to start putting together a motor in a few months.

Here are the parts I have. The car was shipped 4/5/1972.
- WM block - B292 (leap day)
- 7042273 carb - 2031 (late July 1971)
- 7F6 heads - C142
- 1108436 starter - 1B11
- M22 transmission - Came out of a 1972 T/A with mid-September 1971 heads)

I'm iffy on the block, I think the heads are too late, and the other parts may be too early.

I'd like your thoughts.

Since the car will never be "matching numbers", put whatever motor you want in it. Especially if you are going to keep it. If you are building it to sell then I would use one of the SR blocks.