If you can't find a socket with clips, you can get something like Arctic Silver thermal adhesive:
http://www.newegg.com/Product/Product.aspx?Item=N82E16835100005&cm_re=arctic_silver_thermal_adhesive-_-35-100-005-_-Product
(not specifically endorsing Newegg, but they are a pretty no-fuss company)
I've used this to adhere the heat sinks on a number of QuadDoubler-type CPU cards. You can see a little bit between the CPU and the heat sink in this picture:
Just FYI - almost all m68040s in Quadras were made with the exact same mask and feature size, so there's no manufacturing difference between most 25 MHz m68040s and 40 MHz m68040s besides the fact that the 40 MHz parts were tested at 40 MHz in the factory. I've overclocked many 25 MHz CPUs to 40 MHz without problems, and I wouldn't be surprised if they worked fine at 50 MHz in QuadDoubler-type situations.
What'd be nice would be to find a source of Freescale post-2002 m68040s which are made with a smaller feature size, take much less power, and can probably run much faster. The latest (and perhaps last) mask from Freescale is L88M at .57 microns.
I imagine one in a QuadDoubler-type card on a 33 MHz motherboard would be sweet. It might even be possible to run such a CPU at 80 MHz... One of these days I'll find one!
http://www.newegg.com/Product/Product.aspx?Item=N82E16835100005&cm_re=arctic_silver_thermal_adhesive-_-35-100-005-_-Product
(not specifically endorsing Newegg, but they are a pretty no-fuss company)
I've used this to adhere the heat sinks on a number of QuadDoubler-type CPU cards. You can see a little bit between the CPU and the heat sink in this picture:
Just FYI - almost all m68040s in Quadras were made with the exact same mask and feature size, so there's no manufacturing difference between most 25 MHz m68040s and 40 MHz m68040s besides the fact that the 40 MHz parts were tested at 40 MHz in the factory. I've overclocked many 25 MHz CPUs to 40 MHz without problems, and I wouldn't be surprised if they worked fine at 50 MHz in QuadDoubler-type situations.
What'd be nice would be to find a source of Freescale post-2002 m68040s which are made with a smaller feature size, take much less power, and can probably run much faster. The latest (and perhaps last) mask from Freescale is L88M at .57 microns.
I imagine one in a QuadDoubler-type card on a 33 MHz motherboard would be sweet. It might even be possible to run such a CPU at 80 MHz... One of these days I'll find one!