From the pages linked off http://members.iquest.net/~rec/intel_alt/ :
133 MHz internal clock
33 MHz bus speed
4x clock multiplier
486 motherboard (168-pin PGA; 208-pin SQFP)
16K unified write-back cache
Notes: The Am5x86 is essentially a clock-quadrupled 486 processor. The performance increase is gained almost completely through higher clock rate, with relatively few architectural differences.
133MHz to 150MHz (3x50MHz) -- Reports on newsgroups indicate that this is possible, but I have not received email from anyone who claims to have done it. Note that some cards cannot support 50MHz operation, so this could cause problems.
133MHz to 160MHz (4x40MHz) -- Not only is this possible, but it seems to be very popular. In fact, everyone who's emailed me about this chip claims to have overclocked it to 160MHz without problems. They report performance in the range of a P90