Inliners International Forums General Discussion Drive Train 261 in 73-87 chevy pick-up

I am new so here so bare with me, please. I have an 81 chevy pickup that had a 250 w/t350trans. I recently purchased a running 55 261 and would like to put it in my truck. Does somebody make conversion mounts to put this in my truck. I also have a t5 out of 86 firebird 2.8l that I am going to run with it. Any input would be greatly appreciated. Thanks, Mike