[doowopper]

Originally Posted by Accelo

Few engines through automotive history have the same consistency and interchangeability that the Chevrolet Small Block & GM Gen III+ engines have. GM power enthusiasts like us were relieved to find that the GM Gen III engine released in 1997 had essentially the same block bolt pattern at the rear face as the previous Chevy Small Blocks, and the same crank bores for the automatic torque converter pilot journal and the manual pilot bushing area.

However, the crank flange spacing, bolt pattern, pilot bushing bore changes and flexplate / flywheel configurations play importantly into interchange.


https://www.novak-adapt.com/knowledge/gm-crank-spacing

This will help. I didn't know which LS motor or if you have and automatic or manual.
This guide helps a lot.
Check out the LS Swap area of this forum for more information.
It's under the Engine & Drivetrain section.
Here is the link.
https://67-72chevytrucks.com/vboard/...play.php?f=206

Cheers

thanks