Adding auxillary filament transformer?

I have 3 ST70s with octal VTA70 boards (yes, I'm a fan). I've been running them for years with stock power transformers. They run hot, but knock-on-wood, so far no failures. But I'm progressively growing more nervous. I could seek out replacement transformer, but am considering adding a separate filament transformer, such as Hammond 167T6 (6.3V, 12A). I might be able to fit it on chassis between power transformer and board. It would not have much clearance between itself and power transformer for cooling, but I'm guessing this would still be much preferable situation than continued over burdening of the PA060. My electronics knowledge doesn't extend much beyond following directions and soldering, so I ask: Is there any reason this approach is less desirable than replacing entire transformer?

A friend gave me an AC whisper fan from an old computer stack that I set up behind my ST70 to keep air flowing over the PT and LOTs. It makes a noticeable difference in keeping things cool, is not obtrusive and much easier than other alternatives.

j.click wrote:A friend gave me an AC whisper fan from an old computer stack that I set up behind my ST70 to keep air flowing over the PT and LOTs. It makes a noticeable difference in keeping things cool, is not obtrusive and much easier than other alternatives.

thanks for the reply, but the problem isn't merely the heat, it's the fact that using 3x 6SN7 in the driver stage causes total filament draw to go beyond PA060 spec.

Expensive option but if your existing ones are good you could sell them.
http://www.tubes4hifi.com/AMP-PARTS.htm

PS, no personal experience other than owning a VTA ST-120