so my 97 a4 2.8 is the 12v. im considering swapping the heads out for a pair of 30v, if i can.
will the 30v heads bolt right up?
and will i have to flash my ECU or modify it with vag-com?

 

Why???

 

The bolting up part might be the only thing that goes right. The ECU is totally different, the idle control, motor-driven throttle, e-gas pedal, exhaust manifolds, intake manifold, engine electrical harness, etc are all different. For 10% more power not worth it in my opinion.

 

Not all 30v's are DBW, only those '00 and later. However the electronics are completely different, the 12v uses a Hitachi ECU and the 30v uses Bosch. The harnesses, sensors, and plugs are nothing alike, you'd have to basically swap over an entire parts car worth of stuff to make it work.

 

well thats the point. my buddy wrapped his 98 2.8 30v around a pole last week. its getting totaled out, so im going to buy a bunch of parts off of him. he had a supercharger on his so hes buying another 2.8 30v to carry most of it over(SC, ecu, exhaust etc) either way ill easily be able to obtain anything i need for this swap. plus i can rebuild the heads if they need it without sacrificing ripping apart my daily driver yet

 

To be completely honest, 10% power increase caused by the extra valves and diverter valve isn't enough to justify all that work but If you really wanna do it, go ahead. Post a nice DIY of how much fun you had.

Id rather spend money on a nice full stainless steel exhaust system, all the way from after the exhaust manifold to the muffler. Don't get me wrong, I've had crazy ideas before too, but I don't know if the swap makes sense.

 

Prior to beginning work, you may want to inquire from the local government agency responsible for smog inspections where the vehicle is to be operated if an engine not certified for that MY will be able to pass both a visual and emissions test. Usually modified vehicles are rejected without some type of exclusion issued by the government agency.