69 350 with no balancer bolt on crank?

[bigarmzz]

I have a good running 350/300 hp motor out of a 69 SS impala, I drove the car home a few years ago, (body was shot), it only has around 40,000 on it, and it drove great ( until I robbed the motor and transmission Out of it)

Its date coded for 11/68, But it has no crank bolt, no bolt holding the harmonic balance on, appears the balancer is a press fit..? Ive never seen a stock 350 have a pressed on balancer. Can i get some opinions here? What u all think?

I’m really wanting to use this motor but very reluctant because of the lack of the crank bolt

[Steeveedee]

That generation has a press fit harmonic balancer. I quit working as a mechanic in '84 (except on mostly my own vehicles) and has never seen a slip fit harmonic balancer on a SBC- always a press fit. That said, take a close look at the crank. Could the bolt be broken off?

[68Gold/white]

I have no knowledge of of what particular engines did or did not get the bolt, most did. Not all that unusual though. All Chevy small blocks have press on balancers, at least on the first gen engine up until the LT engine.
My 67 283 in my Bel Air had no bolt. When I has the engine rebuilt, my machinist sent to crank out to be drilled and tapped. He said that even though GM trusted that setup, he could not...

[bigarmzz]

Originally Posted by Steeveedee

That generation has a press fit harmonic balancer. I quit working as a mechanic in '84 (except on mostly my own vehicles) and has never seen a slip fit harmonic balancer on a SBC- always a press fit. That said, take a close look at the crank. Could the bolt be broken off?

Thanks for your reply, there’s definitely no bolt broke in there as you can see, it is tapered in the crank, I have never seen a set up like this that didn’t take a bolt in the crank to hold the balancer on

I have never seen this set up before except on the earlier 283’s, do you all think maybe someone tried to make a 327 out of this 350? I suppose that could be possible using the 283 crank to destroke it to a 327..??

[geezer#99]

What's the casting number?

[68Gold/white]

Originally Posted by bigarmzz

Thanks for your reply, there’s definitely no bolt broke in there as you can see, it is tapered in the crank, I have never seen a set up like this that didn’t take a bolt in the crank to hold the balancer on

I have never seen this set up before except on the earlier 283’s, do you all think maybe someone tried to make a 327 out of this 350? I suppose that could be possible using the 283 crank to destroke it to a 327..??

Supposedly all small block internals went to the large journals on the cranks starting in 1968. Block info may or may not tell us enough. a tear down will tell us all..

a 283 crank in a 350 (4 inch bore block) would give you a 302 (yes just like the Z28's).

No telling....

[100%Chevy]

That 350 is for sure a 350?
All 350's are large journal as far as I know.Earlier 327 small journal won't fit without some mods.
And,68 327's are large journal.My 68,327 is tapped and has the bolt to hold the balancer on.
Early on(63/64?)GM started using the bolt on higher hp engines like the 300 hp 327's.
Mike.

[GRADYS Performance]

Gm built many Small Block Chevy engines without harmonic damper bolt holes in the crankshafts. Press fit damper was all that held it on. Upgrade performance motors normally had a Damper bolt.

[GRX]

Originally Posted by GRADYS Performance

Gm built many Small Block Chevy engines without harmonic damper bolt holes in the crankshafts. Press fit damper was all that held it on. Upgrade performance motors normally had a Damper bolt.

^^ That exactly. If memory serves, 350s did not receive crank bolts as a matter of course until some time in 1969. Certain upper performance factory engines did receive them before then.

[Bigdav160]

Yep, my 327 crankshafts are not tapped

[bigarmzz]

Originally Posted by geezer#99

What's the casting number?

-It is a 3932388 block, K808 date code
-Intake manifold it is matching with 3927184 Casting number, K27 8 date
-Definitely 041 heads (Haven’t had the valve covers off to check casting numbers, but I recognize the markings)

by the way, I have no idea why the pics I post are all coming up sideways....??

[geezer#99]

So it could be a 327 too!
What's the suffix code?

[bigarmzz]

Originally Posted by geezer#99

So it could be a 327 too!
What's the suffix code?

HN is suffix code on block

[bigarmzz]

Originally Posted by geezer#99

So it could be a 327 too!
What's the suffix code?

since it was in a 69 impala and not a 68, and it had a TH350 trans wouldn't it then be the 350/300hp? odd, just never seen a 69 350 engine have no balancer bolt....new one to me

just looked up the suffix code-
http://www.chevy-camaro.com/chevy-ca...s.asp?group=12

[geezer#99]

Or it could be a 327.
http://www.nastyz28.com/gm-chevy-cod...s-suffix-5.php

Couple ways to tell.
Pull the pan, check for 2 or 4 bolt mains.
If 4 bolt it's a 350.
If 2 bolt could be either.
You'd need to check stroke.

[GRX]

Those #3932388 were a one year deal. Never seen one in 327 flavor. My vote goes for 350. Could be 2-bolt main, though likely 4. Being earlier 69 block, cast in november of 1968, no surprise the crank snout is not threaded.

[Steeveedee]

327 was still available in the US in '69, and in Canada for at least '70. If any later than that I don't know.

[BCOWANWHEELS]

Sounds like a 283 to me

[bigarmzz]

definitely conflictive thoughts on this, but the impala in question had the original air cleaner on it, and you could tell it was very old, and it had a very old, barely intact "350/300hp" decal

my vote is its a 350, but, I'm honestly still confused about the balancer, but I guess they must have made some without the bolt still up to and including the 69's....learned something from you all like always, thanks!

[BCOWANWHEELS]

Block numbers will tell story