Dimension 4300 cpu upgrade ...vs. MOBO model

Hi All,

My first time posting here. I know this subject has been beaten to death ...I've been going blind reading the scads of posts. Most say this *should* work but there are enough upgrade duds to still give me pause.

One post that caught my eye had to do with the motherboard model or version.

According to the poster, he contacted the Dell Tech folks and they told him the only Dimension 4300 supporting higher than 2.0GHZ are ones equipped with MOBO's begining with model number 9J455 or higher. Apparently the older MOBO's do not supply a particular voltage for the "newer" faster CPU's. Which also means they have admitted, in a sort of backward manner, the 4300 can run faster CPU's ...but only if the MOBO is able to handle them.

Now my Dimension is old enough for Smithsonian status ...it was built in 2001 if the stamp inside the case is any clue as to it's vintage. My MOBO is a 7H374 (apparently made by ASUS according to a quick search). It is running its OEM 1.6Ghz P4, 18mU tech., 256 cache CPU. 

My questions:

Of those of you who have had success with the 2.6 or 2.8GHz upgrade how old is your 4300 ...when was it made?  

Has anyone had success upgrading the older versions of the 4300 (like my circa 2001 model) or are the Dell Tech folks blowing smoke?

Does the 1gig memory capacity have more to do with the A06 BIOS upgrade and WinXP (which I have both of) than any physical limitations with the machine (right now I have 512K)?

What RAM chips is everyone using? If I can't boost the CPU then at least I can max out the memory...

Thanks!