67 TKO LS Motor Mount Compatability Advice

[BaroneDog]

Been reading a lot on this website about the many different LS/Motor Mount/Header/Tranny combinations out there and could not find my exact setup, so wondering if anyone out there has done the following combination in a 1967 shortbed with a low hump:

1. Doug Thorley 323-Y (1 7/8') Headers
2. CPP Sheet Metal Stands
3. Dirty Dingo Sliders
4. TKO 600 Transmission
5. CPP Tranny Crossmember

From what I have read, people have had very good luck with these headers clearing with #1-3 combo above, but I fear that this setup might put the engine a bit too high and cause interference between the TKO and my low hump tunnel. I have seen a few threads that indicate the TKO will clear the low hump tunnel, but did not get much details about the motor mount setup.

If you used a motor mount setup that put the engine lower, did you have to trim the frame rails for headers to clear? From what I read the 67 has a bit wider frame rail near the motor mounts.

There was one thread with a 67 that used the ECE mounts (which sound like they sit lower than the CPP/DD combo) but used the 1 5/8" Thorley 324-Y headers and the photo looked very tight on the driver side, which got me worried about the 1 7/8" clearing in that setup. The Thorley instructions for the 323-Y indicate that the headers should clear, but it sounds like some frame trimming is required for the ECE in the 67, which I am trying to avoid.

Any thoughts and experience is appreciated. Thanks!