Please Help?..456 GTA Suspension Modification

That's funny because I have been reading every thread I can find about the rear shocks as mine recently left a giant puddle of ATF under the right rear wheel. There is a thread that discusses it. The hardest part seems to be what to do with the pump and the extra hydro supply. The ultimate advice was to pay to have the hydro system fixed for good and move on.

Here is my thought process. The 456 is heavier than the 550. While the 550 shocks might fit you may have trouble getting the appropriate ride height so you may have to experiment with stiffer springs until you get it right. The 550 shocks appear to have adjustable pre-load so you should be able to dial in the correct ride height one you get the correct spring. It looks like there were three different spring options built as well so you have a chance to get in the ball park with Ferrari springs and maybe the 456 spring would fit too? Not sure as the 456 shocks are a lot beefier from what I've read. Otherwise your are in the custom spring market (hope you get it right with the first pair).

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Unfortunately, the shock ball joint #12 does not appear to be the same between the cars. My guess is the 456 is beefier. That means the 550 shock probably won't bolt right up to the 456. Some mods there. And if the 550 shock and hardware is not beefy enough all around for the 456 then you have the chance of catastrophic failure.

So if I were to attempt this I would likely try to modify the 456 shock to remove the pump. I would probably try to cap the bomb with oil in it. However the Ferrari system has a minimum hydro pressure that lifts the car so you will need to compensate for that loss. I would then try to get a stiffer spring to get he correct ride height, probably having to look beyond the Ferrari offerings and have some custom made (hope I get it right the first time).

After that I would put the 550 steering pump on the 456 and hope it works.

So that would all get me back to throwing about $4k in parts and labor having the stock shocks re-valved/refurbished + lifetime warranty by one of the high end shops.

 

If either of you decide to go that route I can supply modified rear mounts with the metal to metal ball joint replaced with a Bilstein rubber bushing similar to the way a Corvette shock is mounted.

This will give a vastly improved and more compliant ride especially over tar strips and the like.

I think the only question is the bolt hole spacing on the 550 mount compared to the 456 mount.

Hole spacing on the 550 mount is 140 mm about 5 1/2 inches.

See this https://www.ferrarichat.com/forum/threads/550-rear-shock-mounts.244510/#post-138679221

 

Too late to add on edit:
The screw 159309 in the lower joint is the same in both models so the fact that the ball joint used in the 456 is different from the bushing used in the 550 the ID is the same so the shock should bolt on with no modifications to the lower joint. If the 550 mount will bolt in place I can't see why this couldn't be done.