825i vs 825i S4 rear shocks

My early 825i bottoms out with less than 500 lbs in the bed, even though it's supposedly rated for 1,000 lbs.

I want to try the rear shocks from the 4 passenger (825i S4) since I'd assume they're designed to handle more weight.

Does anyone know if the 2 parts have the same physical dimensions (are interchangeable)?

(825i rear shock: AM137814, and 825i S4 rear shock: AM142276)