63 340 HP timing cover

[Boyan B.]

I was ready to button up my shortblock by installing the harmonic balancer when I noticed that even though piston #1 was at TDC, the mark on the balancer was pointing at about 4 degrees ATDC on the timing cover. The engine came in pieces so I'm not sure I have the right timing cover or maybe the balancer ring has slipped. It's a 8 in balancer with the fins in it. The timing cover that I have has 16 deg BTDC and 8 deg ATDC marks on it. Digging through my stuff, I found another timing cover for 8 in balancers and it has only about 8 marks on it with just an "A" and "0" marks.

How do I tell a 340 HP timing cover and where can I get one?

Thanks, Boyan.

[Duke W.]

Re: 63 340 HP timing cover

The one with "A" and "0" is probably correct. In about '69 (not sure of the exact year), GM changed the damper/scale location of TDC and this later indexing had a separate tab/scale that was attached with the timing cover bolts rather than being welded to the timing cover.

Duke

[Boyan B.]

Re: 63 340 HP timing cover

Both tabs are welded on.

[Duke W.]

Re: 63 340 HP timing cover

Since the balancer is not on you can probably compare the relative positions of the TDC marks on the two timing covers and select the one that is the closest, and consider that the known original cover on my '63 340 HP engine has the "0" and "A", so without being able to compare them side by side, that's the one I would choosae.

Duke

[Boyan B.]

Re: 63 340 HP timing cover

Thanks Duke, I forgot you had an original one. I will email you a photo of the "A" "0" cover just to make sure.