X2 Upgrade

I just bought an S939 X2 4200+ Toledo OEM and am wondering if I can use my S939 A64 3200+ Venice stock retail HSF with it without OC with no issues- I'd swear the CPU is fatter (due to 2 cores?) Will this be a problem?

Also, I have heard many stories of peeps having issues with having to re-install their OS after dropping in a dual-core CPU- what is the likelihood that I will be faced with this problem?

Yes you will have to re-install your OS for sure. Store24

Edit: OK, I'll take that as a "no"...