A couple CPU questions

Ok currently I am AMD but I am returning back to Pentium. I want to go 2.4 with 533fsb. I have been reading alot about 2.4A and 2.4B I know this deals with OC'ing but what exactly is the difference between A and B. Also what's up with C1?

Oh yeh and should I've noticed that some 2.4 cpu's are northwood and some aren't. Newegg has a 2.4 with northwood for about $15 more than one (I guess) without Northwood.

Thx in advance

A 2.4A is a 400Mhz fsb chip. A 2.4B is a 533Mhz fsb chip. C1 refers to the stepping (i.e. revision) of the cpu, and is slightly better than the older B0 revision in terms of performance and overclocking.

ALL 2.4Ghz P4s are Northwood. That $15 difference probably means one is retail boxed and one is OEM (non-boxed).