In some cases street cars that have large engines, extremely high power output, and/or do drag race starts still want quiet rubber mounting. Another trans mount must be added to aid the nose cone mount in doing its job. Back in the early 1970s we had installed our GB 640 solid intermediate mount to stop nose cone breakage with wonderful results. Now we started experiencing the same loose or broken shift housing problems with street cars. It was obviously being stress loaded way beyond its capabilities. For that reason the GB 643 rubber mounted intermediate housing mount was invented in 1977. Yes, straps and all types of configurations were tested and nothing even comes close in providing the required support, with practically no additional noise transfer.
So here's what to use: GB 642A hard rubber nose cone mount, two GB 642P hard rubber pad mounts, GB 643, and GB 645A (646A, 647A). This is the street set-up that is being run in Gary Berg's 12 second street car for daily driving and all out drag racing with absolutely no wheel hop. The wonderful part is that it can be drag raced from stop lights or at the drag strip with the same combination without any wheel hop.
Do not misinterpret this as being for all out race applications (as stated above). They do still require the GB 640 weld in solid mount, the GB 641 solid yoke mount to tie the frame horns together with the trans, and a GB 645 or GB 646 Berg quality solid mounted traction (engine) bar with proper preload.