Caster blocks and 17" wheels questions

[ThomasSF]

Hi,

I am going to put 17" wheels on my 89 944 NA. From what I have read, it is advised to upgrade the caster blocks to 968 style caster blocks when doing so.

My questions are: how many are there on my car (rear AND front?) and which ones should I replace?

Also, I am not sure I understand why and how wheel diameter affects this particular part, any explanations?

Thanks!

[Techno Duck]

One per control arm, you only need two. They are where the rear of the arm mounts to the body of the car. Larger wheels put more stress on the suspension components due to increased mass, extra grip and overall diameter. The stock caster blocks are essentially all rubber and will flex significantly under*cornering loads, this in turn means the control arm is moving in relation the the chassis. The 968 parts have much less rubber.

I'm not sure if the year if your car is in your sig (using mobile Pelican), but if your car has the stamped steel arms (early offset, pre '85.5) you can't use the 968 caster blocks anyhow. There are aftermarket options from Weltmeister and RacersEdge in that case.

[rickharrison]

its an 89 NA...the updated blocks will work fine.