1968 Polara 383 Crankshaft Questions

[GMPolara]

I've been working on doing a rear main seal and found allot of notches cut out of the crankshaft. If there's any machinists here I'm curious why these were made. Check out my video:
Dropbox

 

[Davea Lux]

Those cutouts can be made to balance or re-balance the crank. On the driver side of the block, there is casting date, that should tell you if your car still has the '68 engine. Since you already have the main cap off, pull the bearing from the cap and check the back side of it, if the crank was turned at some point, the bearing will usually be stamped with the under size such as .010 etc. A crank that has been turned will also need to be re-balanced which might explain the ragged nature of the cutouts.

Dave

 

[Lefty71]

I watched your video.... i think all those notches are factory stock work. I did not see anything that i havent many times on bone stock mopar bottom ends.

 

[GMPolara]

The rest of the car I've found to be unmolested. So that would make sense Lefty.
I've decided to pull it and do a rebuild. Fingers crossed. Thx all!