Here's why it's complex and what you'll need to consider:
* Different Engine Dimensions: The 350 V8 is considerably wider and longer than the inline-6. This means the existing motor mount locations on the 1968 frame are completely unsuitable.
* Frame Modifications: You'll likely need to modify or reinforce the frame to accommodate the larger engine.
* Custom Motor Mounts: You'll have to fabricate new motor mounts. This usually involves using aftermarket motor mount plates or making your own from steel. These mounts will connect the engine to the frame rails. Many engine swap suppliers sell these, but they're often specific to the year/model/engine combination. You'll likely need to locate ones for a SBC (small block Chevy) in a 67-68 C10 (the chassis code for your truck).
* Transmission: The transmission from the 350 will also need to be considered, and may require an adapter plate to mate to the existing transmission crossmember or a custom crossmember.
Finding the Information:
1. Online Forums: Search forums dedicated to classic Chevy trucks (e.g., Chevrolet Forum, ClassicCars.com forums). Many experienced individuals have documented similar swaps, and you'll find invaluable advice, photos, and even custom mount fabrication plans.
2. Engine Swap Kits: Some companies specialize in engine swap kits for classic trucks. These kits may include motor mounts and other necessary components, making the process easier. However, they're often expensive.
3. Professional Mechanic: Consider consulting a mechanic experienced in engine swaps. They can assess your truck and advise you on the best approach.
In short, there's no simple answer to your question about motor mount location. It's a project that demands careful planning, fabrication skills, and potentially professional assistance. Start by researching online forums and exploring the possibility of using a pre-made motor mount kit. The "inches" you're asking for will depend entirely on your custom fabrication.
