'68 327/300hp

[Richard S.]

I'm thinking about installing a 350 crankshaft in the 327. Any experience/tips? Thanks

[David L.]

Re: '68 327/300hp

According to my 1969 Chevrolet Parts Catalog (Oct. 1968) the 1968 Corvette w/327(exc. SHP) used crankshaft # 3930809 with early 1968 models using 1967 engines (crankshaft # 3889304, ID # 3782680, small journals, 2.30" main & 2.20"rod) built to 1968 specifications. The 1969 Corvette w/350 (exc. HP) used crankshaft # 3932444 (ID # 3932442,large journals, 2.45" main & 2.10" rod).
I believe that the 3930809 crankshaft has large journals but you should verify this.
Which 1968 engine do you have? You can tell which crankshaft you currently have by the shape of the crankshaft flange (refer to "1965-69 Chevrolet by the numbers", page 79, by Alan L. Colvin.

Dave

[Philip A.]

Re: '68 327/300hp

Richard
Recommend you change the post title to reflect the question, such as 350 crank in 327 block. There are folks on here that could probably answer it based on actual or bench experience.
Phil

[Gene M.]

Re: '68 327/300hp

Richard,
It would just make your 327 into an what everybody has a 350.

[Joe L.]

Re: '68 327/300hp

I'm thinking about installing a 350 crankshaft in the 327. Any experience/tips? Thanks

Richard-----

Except if it happens to be one of the very early engines with small journal crankshaft (and, personally, regardless of the P&A catalog disclaimer, I don't think any were ever installed in Corvettes), installing a 350 crank is quite simple. You do have to change pistons and harmonic balancer, but everything else remains the same. Doing this converts a 327 to a 350.

So, how can you tell if your engine has the large journal crankshaft? Very easy. If it has a casting #3914678 block, it has the large journal crankshaft.

[Richard S.]

Re: '68 327/300hp

Richard-----

Except if it happens to be one of the very early engines with small journal crankshaft (and, personally, regardless of the P&A catalog disclaimer, I don't think any were ever installed in Corvettes), installing a 350 crank is quite simple. You do have to change pistons and harmonic balancer, but everything else remains the same. Doing this converts a 327 to a 350.

So, how can you tell if your engine has the large journal crankshaft? Very easy. If it has a casting #3914678 block, it has the large journal crankshaft.

Thank You for responding. I will probably pull the engine in the next month. The information will help the decision making process.

Regards, Richard