I hope you can adjust the Instant Center on those rods. The same geometry was used on the GM A-bodies like Chevelles. Those cars had the instant center too far towards the front. The rears would hop under hard acceleration. The cure was to relocate the upper bar attachment to the axle, higher. This shortened up the instant center and voila! no more hops.
R.
Remember, this is a street rod, not a drag car. There is a difference in application between a 4 bar and a 4 link rear suspension. Mine is a triangulated 4 bar - best suited for street rods / "g" machines. 4 links are best suited for drag /race cars ( much more instant center adjust ability for track conditions).
