McIntosh MC402 as monoblock?

I do have the MC402 to drive Shahinian Diapasons, and, though I love the sound, I keep thinking about going monoblocks. There is the way of two MC501s, or getting a second MC402, and connect it as a mono-amp. Did anybody try this, or compare two 402s to two 501s?
Also, my speakers offer 6 ohm-resistance, and sound best from the 8-ohm-tap. With a 402 used as monoblock, electrical impedance drops to 4 ohms: Is it still possible to use them with a 8- or 6-ohm-speaker without losing out soundwise?
I have 501's and I did compare them to the 402's. Both are excellent options, the only difference was the 501's ability to offer just a little more of everything, bass, detail, texture, and transparency....I mean just slightly more. The biggest difference for me was more of a sense of ease when driven. I matched them with Thiel 3.6's and they don't break a sweat. The 402's did an excellent job as well, there was just a bit more with the 501's.

I find they respond to IC's and speaker cables but every power cord I have tried falls short of stock. They seem to lose some of the excellent Mcintosh midrange.

I can't answer your other question regarding 402's as mono's.

Good Luck.
the mc402 is not meant to be ran as a monoblock, the only current 2 channel amp mcintosh makes that's meant to be ran as a monoblock (bridged) is the mc252, what your thinking of doing with 2 mc402's is meant for vertical biamping plus if you run your amps hard while pushing 4ohms to an 8ohm speaker the amps will get roasting hot & quickly go into protection mode (been there & done that :(

i had the mc402 & the mc252 at the same time & i thought both amps were so close in performance that i ended up keeping the mc252 over the 402, i then added a 2nd mc252 & ran them both bridged as monoblocks & the performance was excellent but still not like the mc501's.

i have ran a ton of mcintosh 2 channel amps as monoblocks & i liked them too but none compared to the mc501's or mc1201's,i still havnt tried the mc1000's so i cant comment on them.

the better move would be to sell your mc402 & upgrade to the mc501's instead,if you bought your mc402 used at $3,500 & found another mc402 for the same price you would still have 7k into the pair & mc501's can be had for less than that brand spankin new .

100 percent agree with Bigjoe's (Mike) comments, I have had all three in my house. I own the 252, and use it with quality but modest speakers, assuming your source and pre are up to snuff the 501s are the better sounding amps. To run the 402 in mono would technically raise the distortion, and increase output by 3db,but that aside there are other aspects such as fullness and a more open sound that specs can't relay. But what you are talking about is for the same and maybe less money you could get the 501s....that's the play.
I have a pair of Thiel 7.2 which were driven by the MC402 for a long time. Recently I experiemented bridging the MC402 (closely following the user guide and using a set of jumper wires), and powering only one speaker. The difference was a noticeable jump in dynamics, bass, sound separation, and overall more fun to listen to. Because I only have one MC402, I don't know what it would be like having two of them bridged as monos, but I am sure they will be great with my Thiel 7.2.