Hi! there dont waste your time with a 68881 get a 68882 its much quicker and although quite expensive would be imho
the better option. :-D With regards to fitting its quite simple if you look at your 68030 cpu it should have a little arrow type pointer on the top lh side, your maths copro is orientated the same way if I remember correctly.
Hope this helps mate.
cheers

unfortunatly, the short of it is "no".
reason being is that it gets fed the same clock signal as the CPU, and i'm not sure how long an 881 would last at 50Mhz given that its max speed was 25Mhz (or slightly overclocked to sync to the amigas master clock at just over 28Mhz)

the 882 started at 25Mhz versions up to 50Mhz versions.
although i could only get hold of a 40Mhz version of the 882, it seems happy on my blizzard running at 50Mhz.

i belive that they are pin compatable, as for comparitive processing power, i understand that the 882 is about 10% faster at the same clock speed than an 881.
881 = ~240KFLOP/s at 25Mhz
882 = ~264KFLOP/s at 25Mhz
the 882 advantage was being able to be stable at higher clock rates.
for sake of completeness, 040 = ~3500MFLOP/s at 25Mhz

so although they would plug into the same socket, on the blizzard this is not a good idea unless it was running at 25Mhz.

just out of interest, what speed (clock) does it run on your memory card?

--edit--
my bad, 68882's came in at 16 and 20Mhz aswell. how could i forget the early A3000's?

hmm, maybe i'd better heatsink it and leave the trapdoor cover off. not sure i like the idea of it going pop  :-(
but then it gets fired up infrequently. but when it is on, it's usually on for a whole weekend...

and a 25% overclock is pushing it a bit  :-D

@ darksun9210
"just out of interest, what speed (clock) does it run on your memory card?"

No idea how do I tell?