front of engine set up for 1969

[66fs]

so a few pieces of info to clarify:
forged to cast change happened mid year in 1972 so you might have a forged engine depending on when the engine was built as opposed to when the car was assembled.

You have to match the timing cover, the harmonic balancer, both 69 and down or 70 and up. They will bolt in place but timing mark will not match the scale in the timing cover. The drivers side lower radiator hose and power steering pump for 69 will cover up the timing marks on a 70 and up timing cover and of course the water pump and radiator have to be matched for drivers or passenger side. So the only reasonable way to approach this is to have the timing cover, harmonic balancer, water pump and radiator (and the power steering pump and brackets if you have PS) be either 70 and up or 69 and down. There are also differences in the pulleys so add that to the list. The A-body year and motor year make no difference as long as everything from the front of the block is matched.

The nightmare I am facing is a non-original engine that has been in a car buried in a shop for 20 years. We know it has a 69 and down water pump and radiator and a 70 and up timing cover, now trying to figure out which balancer it has to figure out how to get a matched 69 and down set up that is complete.

66-69 balancers were all the same, 273, 318 and 340 except the 318 automatic. You can get them new from BHJ but they are slightly smaller OD and not sure if they have the offset bolt, but I could check. But you need to call them. I can tell by looking which balancer is the 66-69 if you can post a picture. There is a number cast into the back of the hub also, 2658458. Notice the shape of the holes and the angle between the "0" mark and the crankshaft key way. 70 and up have the "0" mark and the crankshaft key way almost in line. The originals can also be rebuilt if the elastomer looks bad.

 

[nutz]

But don't think you can match a cast crank 340 to a pre 70 cover

 

[66fs]

But don't think you can match a cast crank 340 to a pre 70 cover

True, but I would not run a cast crank in any 340. However you could find TDC and add a timing tape to the damper.

 

[Mike69cuda]

What’s stopping you from running earlier timing cover on a 72-73 340? I thought they all interchanged, except for the timing mark issue.