Hello all!

Ive got some questions i cant answer over here. I drive a 2008 Chevy Cobalt, which I am n the process of building the chassis on. I am to the point where its damper and brake decision time. Heres where you come in. I would like to know the following:

<u>Will any 5 lug Astra brake setups physically bolt onto current Vectra(Epsilon) steering knuckles?</u>

In the US the Cobalt steering upright and the Pontiac G6/Malibu/Saab9-3 steering uprightss are all interchangeable, save for bearing mounting, I have modified Pontiac G6 uprights that i will be fitting to my car, I would like to fit Astra brakes. I am aware of the 314mm Saab upgrade for the Vectra, but the caliper is too large, the Cobalt has a 54mm single piston(or 38mm 4piston) setup so the much larger calipers from the big cars wont work with my master cylinder.
<u>
Could anyone tell me the diameter of the Vectra front strut shaft where the upper mount nut threads on? Additionally would it be possible for any of you fine ladies and gentleman to take a photograph of a front strut and provide accurate but basic dimensions for it?</u>

Again, Since Ill be using G6 uprights I know that Vectra/9-3 dampers will physically bolt to them, but I need to know if I can use my stock upper mount, if the stabilizer endlinks attach in similar positions(rear section of strut body) and what height springs I would need to use. The Cobalt is a true parts bin special, its ever so loosely based on the Astra G, but several bits are much more Vectra like, and some of it is US only. There is very limited damper selection for the 'Balt, I would like to be able to fit some Bilsteins, I currently run the very nice Cobalt SS/TC dampers which are twintube KYB in front and monotube Sachs out back, but would very much like to switch to full monotube Bilsteins, Koni is the only reasonably priced damper in the States for the Cobalt(Delta) and I dont like Konis fondness for excessive compression damping and relatively little rebound damping.

Any and all help will be greatly appreciated, Ive got very few options if you guys cant help, Ill just have to start buying things just to measure.