I may have to pull the engine out of the Cutlass this weekend. I think I may have spun a rod bearing, not sure yet, but that's beside the point here. The engine in it is an older 350 cicra 1969. The crank was never drilled for a balancer bolt. The original balancer spun on itself making it impossible to time by the indicator. Will an internally balanced balancer of the same diameter work in this situation? I figure if I have to pull the engine out, now is the time to change it...along with that POS chrome timing chain cover I put on it.

I may have to pull the engine out of the Cutlass this weekend. I think I may have spun a rod bearing, not sure yet, but that's beside the point here. The engine in it is an older 350 cicra 1969. The crank was never drilled for a balancer bolt. The original balancer spun on itself making it impossible to time by the indicator. Will an internally balanced balancer of the same diameter work in this situation? I figure if I have to pull the engine out, now is the time to change it...along with that POS chrome timing chain cover I put on it.
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Sorry but you have lost me,, what you are asking?? :confused:

If I understand you, yes any neutral damper will work & any small block damper will fit the crank, they are all the same diameter (the crank snout)
I would also have the crank drilled for a bolt while you can get to it.

i'm pretty sure that all factory 350 cranks are drilled for a retainer bolt as are the 68&later-(302/307/327/400)engines. the same size internal balanced balancer will work, but you will need to verify the tdc mark location on the balancer or mark your own for timing purposes...

The crank is not drilled for a balancer bolt, it's just pressed on. It was like that when I got the engine, which was in one of the chevelles I bought years ago, and it's been like that since I rebuilt it and put it in the Cutlass. I suppose what I am looking for is a casting number(s) that are for 69-72 350 balancers that all have the same timing mark on them. The only other thing I was worried about is a difference between one that uses a retaining bolt and one that does not (IE the balanxer walking forward).

Tom,
There is no difference as far as the part that goes on the crankshaft. The ones that use a bolt are also a press fit onto the crankshaft. Do yourself a favor though like Mike said and drill and tap the front of the crank for the bolt. A lot of damaged dampers are from them being "beat" onto the crank. With the hole tapped, you can use an installer and do it correctly. It is very easy to drill the crankshaft if you have the engine on a stand. Just back it up to a workbench or wall to keep it from moving and drill away. I have done several of them after the engine was assembled. About a 15 minute job. Keep the shop vac handy to clean up any filings.

IIRC, the correct thread is 7/16-20, no? :confused:

Right.

pdq67

If you crank is not dilled for a balancer bolt I would say it is an older motor not a 350. They were all drilled. I would run the numbers on the block. If it is un drilled it not a large journal motor. The press on balancer motors are really old.

My 1969 307 (original, untouched) had a press on balancer.

Well if your 307 might have but i doubt a 350 would have had a press on balancer. I think he needs to run the casting number and find out what he has

If you crank is not dilled for a balancer bolt I would say it is an older motor not a 350. They were all drilled. I would run the numbers on the block. If it is un drilled it not a large journal motor. The press on balancer motors are really old.
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I learned many years ago to never say "all" or "never" when it comes to GM & what they did & did not do at certain times. ;)

I can tell you there are most certainly non drilled large journal 3.48 stroke cranks as I have drilled them but I cannot verify what year they are, there is no way to do this.

If you crank is not dilled for a balancer bolt I would say it is an older motor not a 350. They were all drilled. I would run the numbers on the block. If it is un drilled it not a large journal motor. The press on balancer motors are really old.

Nope, I know for a fact it's a 350. It is an early 350 though, casting date on it is August 1968, I pulled the valve covers today to find out what was going on inside the engine and checked the casting date. Found out it was a loose rocker arm, not sure how the nut backed off though, unless the stud is coming out of the head. I readjusted the valves and it seems to be ok. So for now, the spun balancer stays on, I'll worry about it later. I'm just glad it wasn't a rod bearing. I took it out and thrashed on it after I was done fixing it to make sure :)