420A Overbore my 98 GS 420A?

[freeride6772]

Im looking to overbore my 420a, I have looked over the threads and really didnt find anything usefull because my 420a is not heavily modded. I would like to do .040" over.

Is that the largest that I can go?
What should I do about the head gasket?
What other modifications are needed?

Thanks for the help

 

[Locke]

The 420a has very thin cylinder walls, there is not enough metal that can be removed to have any appreciable gains. You CAN bore it safely 0.040" over, but you won't notice any difference, and it will just cause problems later if you need to bore the cylinder's to repair cylinder damage.

It is best on the 420a to only bore as needed. If you want more displacement, look into a 2.2l stroker, or a 2.4l swap.

 

[Defiant]

Overboring for output is seldom worth the cutting when you're only dealing with four cylinders.