if you have a lot of squat on acceleration I don't think it's the shock. The coil spring or spring is to soft. Maybe old and weak.
The shock controls rebound.
Dwight
The Role of Springs in
How Springs Work
Springs cushion the ride of a vehicle according to the principle of sprung-to-unsprung weight ratios. A farm wagon with no springs represents 100% unsprung weight. In this example, if springs are installed between the chassis and axles, the sprung-to-unsprung ratio might be 90% representing the chassis weight and 10% representing the axle and wheel weight.
As a vehicle gains speed, the springs begin to absorb the impact of striking irregularities in the road surface. As vehicle speed increases, a stiffer spring rate is required to keep the axles and wheels in contact with the road surface. This is why high-performance vehicles tend to use stiffer suspension systems than regular passenger vehicles.
Because a compressed spring will ex*tend in a violent fashion, shock absorbers must be used to dampen the spring’s compression and extension cycles. Without dampening, a spring’s violent com*pression and extension would cause a vehicle to lose control on a rough road surface.
As rebound control deteriorates due to normal shock absorber wear, the vehicle will begin to experience poor ride, steering response and handling control. In addition, tire wear will be accelerated due to tire scuff caused by the suspension geometry operating out of its normal range. This is why shock/strut manufacturers are adamant about the regular inspection and replacement of worn units.
In general, the compression and extension characteristics of the shock absorber must match the compression and extension characteristics of the spring. Since stiffer springs don’t normally experience extreme ranges of travel, less dampening or rebound control might be required for normal driving. Softer-rated springs, on the other hand, may require more dampening because they tend to experience more compression and extension and, thus, make the shock absorber work much harder.
For performance applications, it’s essential to remember that the sway bar must also be included as part of any spring or shock absorber package. In any modification procedure, spring rate, shock absorber dampening and sway bar capacity must be matched to vehicle weight, chassis design and driving conditions for maximum handling, load-bearing capability and driving comfort.