The LA Motor "Block"
I sonic tested a few blocks and found the following for thrust (thinnest point):
71 360 bored .030 .125
72 360 bored .030 .134
72 360 std. .220
73 360 std. .185
72 360 std. .190
77 360 std. .175
68 340 std. .137
So you can see it varies allot and the 340 really blew my mind.