[techinspector1]

It's possible all the threads were pulled out by a previous owner, not having a good bite to install the damper and yanking the threads out of the hole. I never saw any crank other than a 265 or 283 that wasn't threaded.

[bigdog7373]

It has a hole a little less than 1/4 inch deep and then it's solid. Maybe an aftermarket crank? idk

[techinspector1]

Originally Posted by bigdog7373

Alright, I'm in the process of building a chevy 350 and I just pulled the harmonic balancer off so i could get at the cam. The problem is that the are no threads in the end of the crank to get the balancer back on... How can i get it back on without drilling and tapping a hole in the crank? It has a hole a little less than 1/4 inch deep and then it's solid.

Let's go back to square one. How do you know it's a 3.480" stroke 350 crank. Please don't just say "I know". Have you measured it? How did you measure it? Did you change pistons? What compression height piston did you use? What's the bore of the block? Did you sonic check the bores for wall thickness? What's the casting number on the back of the block?

[1932bantam]

listen to tech, never seen a 350 with out threads in the end of a crank . i can't recall any large journal without threads. maybe s journal 327?

[bigdog7373]

The numbers on the block are 3932388. The numbers on the crank are 3932442. The block is defiantly a 350, but it says the crank can be a 350 or 305. It has a 3.48 stroke. The bore is 4inch too. That sound like the recipe for a 350 to me.

[cobalt327]

I can tell anyone who wants to know that there are- positively, w/o any doubt- 327 LJ cranks that had NO balancer hole OR threads.

The 327 was from a 1968 Impala in my case, actually the first LJ 327 I ever owned, ca. 1973. Matching engine VIN and suffix.

[bigdog7373]

I don't know whats up with this thing

[cobalt327]

Blurry. Can you see it in person well enough to see there's not a broken off bolt in the hole?

[cobalt327]

What is the casting date and casting number from back by the distributor?

[bigdog7373]

Originally Posted by bigdog7373

The numbers on the block are 3932388. The numbers on the crank are 3932442. The block is defiantly a 350, but it says the crank can be a 350 or 305. It has a 3.48 stroke.

Those are the only numbers i can find on the block and crank. And there isn't a broken off bolt.

[cobalt327]

Originally Posted by bigdog7373

Those are the only numbers i can find on the block and crank. And there isn't a broken off bolt.

Likely an early 350 production piece before the cranks got the full hole/bolt.

[bigdog7373]

That's what i was thinking.

[Frisco]

Here is a drawing I made several years ago to manufacture a simple drill guide to enable an individual to drill the crank snout with a hand drill. Left click for a larger view.

This will not require that the crank be removed from the block. If access is available (radiator removed) it may also be used without removing the engine.

Slip the drill guide over the crankshaft snout and hold in place. Using the correct size drill (25/64") for a 7/16-20 tap you can simply drill the hole in the crank with a hand drill.

A second guide can be manufactured with a 7/16" diameter hole in it instead of the .391" hole. This guide can then be used to guide the tap in squarely.

I originally stated that the guide material should be A-6 tool steel and hardened. This is not necessary for a one time use. Just use cold roll steel.

FYI. The tap is RIGHT HAND threads.

NOTE:

Use lubricant liberally when drilling and tapping. Thoroughly clean out all chips and lubricant after drilling and tapping.

[bigdog7373]

Originally Posted by Frisco

Here is a drawing I made several years ago to manufacture a simple drill guide to enable an individual to drill the crank snout with a hand drill. Left click for a larger view.

This will not require that the crank be removed from the block. If access is available (radiator removed) it may also be used without removing the engine.

Slip the drill guide over the crankshaft snout and hold in place. Using the correct size drill (25/64") for a 7/16-20 tap you can simply drill the hole in the crank with a hand drill.

A second guide can be manufactured with a 7/16" diameter hole in it instead of the .391" hole. This guide can then be used to guide the tap in squarely.

I originally stated that the guide material should be A-6 tool steel and hardened. This is not necessary for a one time use. Just use cold roll steel.

FYI. The tap is RIGHT HAND threads.

NOTE:

Use lubricant liberally when drilling and tapping. Thoroughly clean out all chips and lubricant after drilling and tapping.

Thats pretty beastly man. I'm gonna do that and it should be easy with the engine on a stand. Thanks man

[weedy64]

When I was a teen my 1st car was a 69 Chevelle Malibu with the original engine a stock SBC350 2-bolt and it did not have a harmonic damper bolt.

I wish I still had that car.

Glenn