plus if you lower it with the spings i think the air shocks will try to compensate for it and you will be the same height in the back anyways it'll look like you have a shackle lift like the old chevelles

Thanks for the part #. I am having a hard time finding very many aftermarket pieces parts. Think I found a brake package at w-body store tho.

you wont find too much for these aftermarket couple of other sites for ya are
3800performance.com
zzperformance.com

and 1 more i almost forgot
intenseracing.com

So how do I know what will fit and what won't? Like a strut tower brace, performance suspension parts, things like that?

Don

Thanks for you help btw

the GXP bonneville has a strut tower brace that comes stock if you can find one in the junk yard it would be cheaper than goin to gm not sure of the part# or price from gm nor where to get one aftermarket
as far as suspension they dont have much of anything that i have found yet however go to rockauto.com and they will have the kyb struts and the max airs for pretty reasonable also there is a discount code for us to use in the lounge i believe, that comes in handy when cash is short.
our cars are different cause of the air suspension in the back so suspension will be difficult.
i have the max airs and the do very well in cornering and holding the rear up when ya punch it the kyb struts i hear are very good upgrade for those of us that like to corner fast and basically drive like nascar worth the money

Any particular year of the GXP Bonneville that I should be looking for?

GXP was only availible in 2004 and 2005 then the bonneville line was killed