Calling David Hayward....
 

Need EX-Purt advice on GM-Chev engine block

Looking at a 261....casting number 3769717...1958-92 period with XXXX848 235 head.

Can't seem to find any reference or meaning of serial number which reads W 312809.

I was told it came from a pickup truck..... but it has these punny little 3/8 oil holes on the side of the block. My other 261 block which came from a 5 ton Chev truck had 3/4 oil line to the full flow filter.

Would I have a Canadian Pontiac engine.... or a small 1/2 ton pickup engine with only by-pass filter....???

Stumped???? but wise enough to know where to ask!!!

Bob C.

Answer?
 

1. # 3769717 - 1958-62 261 Block
2. W 312809 = Windsor, Ontario, buiilt 261
3. The engine number suggests as 1962 unit. The casting date code on the block will confirm.
4. Head # 3836848 was a 1955-56 Canadian 235 unit..a hop-up item to increase compression ratio.

How's that mon ami?

OL' reliable......
 

Thanks David

......reassuring information. I assume then that a 1962 block must have.... should have.... full flow oil filtering capabilities. We will verify that possibility before we fire it up by priming the oil galleys with an electric drill with and with out the by pass installed to see if oil is in fact going up to the top end. we usually use a clear vinyl tubing for the by pass which allows you to see the oil flowing...... then check the top end with the valve cover removed....... messy but effective.

With the solid 3/8 steel oil lines it would be feasible to install the spin on filter base in any practical location.

I may need your help to decode the cast date.... I believe I will be looking for an alpha/numerical code in a small rectangle cast in the block side .......seemingly held in place by what appears to be simulated screw heads......

Now I need to bug Phil to see how he is doing with his 261 rebuild.

Thanks again.

Bob C.

Date code
 

The code will be in the form:

A TO L = JANUARY - DECEMBER INCLUDING "I"
1 TO 31 = 1ST TO 31ST OF EACH MONTH
0 = 1960; 1 = 1961; 2 = 1962