I heard that I could bore the stock 87mm in the 98 lude to 90mm and what would the displacement be? or what could i expect from this?

 

blow a cylinder wall?
u are planning to bore it out and leave it NA
or go forced induction?

~boom

 

I would be resleeving it with darton sleeves and putting in je pistons and eagle rods. i was planning on a fmax turbo kit running 12+ psi. If you have a better idea to get more power i would greatly appreciate it.

 

honestly

i guess u r planning to make this a project car?
and ie void ur warranty
if you are gonna work an engine i would recommend the h22a1 or h22a series because they have a closed deck block and the h22a4 (ur engine) has an open deck block which has less rigidity

in this case i would recommend selling your a4, and buying a closed deck block and working that

just my .02

~boom