Help Me with This Argument

[Sparks425Ex]

Me and My friend are in an Argument. He thinks that boring out his 400Ex to a 406 and adding a 10:1 Piston is gonna give him a buncha power.

I told him that just boring out a quad without adding a cam isn't gonna show him very big gains.

Who is Right? I am pretty sure I am.

[Taco]

he will get lowend gains but that is about it

i've ran my 416 for a while without the cam and it gave pretty good gains.. not a huge difference but anything on these small engines is helpful.

[Texan32]

He's also not going to see much of a gain since he is only going to a 10:1 piston. I thought factor was 9.5:1? From what it seems, if your going to do all the work to pull the motor apart, he might as well get the 11:1. Thats when it starts to wake up.

[YZROOSTINYA]

i believe stock is 9.1:1

xr is 9.5:1 i think???????????