KT150s in Audio Research Reference 75 (non SE)


Hey all.  Need some advice. 
I've just dropped in KT150s into my Ref 75 (non SE). 

I purchased "perfect pairs" from TheTubeStore.  

I cannot bias them.  They are all too hot.  There are a couple (of the 4) that if I turn the bias pot all they way down will get very close to the bias range (per the needles).  There are another two that even with the pot turned all the way down are reading past the bias range and the needles are about 7mm beyond the bias range. 

Two questions:
1) Am I doing something wrong?
2) Will it hurt anything to run this a little over the ideal bias range, or just shorten the tube life?  Will it impact sound? 

I thought KT150s were drop in for KT120s.  Am I wrong? 

Thanks!

jo1mtb
Thanks very much for the reply.  Interesting.  I read several posts here where people had great success and were just dropping them in.  Some said they didn't even have to adjust bias.  
I believe Minor1 is correct.  If iit was my amp I would call Audio Research and ask.  Since they design and build them, they will have the correct answer for you.
I spoke with the Audio Research technical expert about 2 months ago.
I also spoke with George Meyer rep and the actually do the upgrades to SE and also said you should not use KT 150s without the larger transformers and other work. 

I believe them

enjoy