Will a 1983 Chevy pick-up cab mount on 1985 chassis?

It's highly likely, but not guaranteed. 1983 and 1985 Chevy pickups were very similar, especially in their chassis design. However, there might be minor differences in the frame mounting points that could cause issues.

To be absolutely sure, you need to:

* Compare the frame dimensions: Carefully measure the cab mounting points on both the 1983 cab and the 1985 chassis. Look for any variations in the holes or the overall dimensions of the mounting areas.

* Check for body mounts: Ensure the body mounts themselves (the rubber bushings) are compatible. Even if the frame is identical, different mounts could create problems.

* Consider sub-models: The specific model of the truck (e.g., C10, C20, C30, long bed, short bed) can affect the cab and chassis dimensions. Matching sub-models increases the chances of compatibility.

Without a direct comparison of the parts, there's no definitive yes or no. The best approach is a careful physical comparison before attempting the swap. Minor modifications might be necessary in some cases.