Here's why and what you need to consider:
* Crankshaft Differences: A 7-bolt crankshaft is significantly different from a 6-bolt. It's not just the number of bolts; the dimensions and overall design are different. This means the flywheel/flexplate designed for the 7-bolt crank won't fit the 6-bolt.
* Block Differences: The 7-bolt and 6-bolt blocks are different. This affects more than just the crankshaft mating surface. The block itself might have different bolt patterns for transmission mounting, potentially causing incompatibility with your automatic transmission.
* Transmission Compatibility: Even if you *could* somehow adapt the flywheel/flexplate, the automatic transmission from a 7-bolt engine is *very unlikely* to directly bolt to a 6-bolt block. The bellhousing (the part of the transmission that bolts to the engine) has different bolt patterns and possibly different dimensions.
What you need to do:
1. Realize this is a major engine swap, not just a crankshaft swap: You're essentially doing a complete engine swap, not just swapping the crankshaft. A 6-bolt engine block, along with its associated components (oil pan, intake manifold, etc.), is needed.
2. Obtain the correct flywheel/flexplate: You need a flywheel or flexplate specifically designed for the 6-bolt engine *and* your automatic transmission. The part numbers will be entirely different.
3. Verify Transmission Compatibility: Check to ensure your automatic transmission is compatible with the 6-bolt engine. This might require researching specific transmission codes and engine codes to confirm compatibility. You may need a different transmission.
4. Professional Assistance: This is a significant mechanical undertaking. Unless you have extensive experience rebuilding engines and transmissions, seeking professional help from a qualified mechanic is strongly recommended. Improper installation can lead to serious engine damage.
In short, this isn't a simple bolt-on modification. You need to plan a complete engine swap, acquiring the correct 6-bolt engine, transmission, and associated parts. Trying to force the old components to fit is almost guaranteed to fail and could cause damage.
