Are the Hurst 4 speed shifters and rods compatible with the T10 transmissions found in the 65 and 66 Gran sports?
Not sure exactly what you are asking, but a Hurst Comp Plus shifter was avail for the 65-6 GS. There was an old Car Craft article (mid 1990's?), which was one of the write-ups done on the 66 GS vert project just restored by Sean @ Paintworks, and they used the shifter and rods listed for a full size Chev (1963-4?). Their pn's matched what was on the 4 speed GS I had bought. Here is some info from my notes: >>>From my Silver GS: Shifter: 304019 Mount: 2223 Shifter Rods: 2139R R2138 F3404 There's a board member, 'Crash' that had shifters avail a few years ago. https://v8buick.com/index.php?threads/nib-hurst-shifter-for-1965-66-a-body.228702/ Here's a pic of the install instruction sheet from his thread. Note the pn's for the shifter rods: first-second: 2138 third-fourth: 2139 reverse: 3404 <<<<
Years ago I broke my muncie, well actually it was mostly broke when I got it. I sourced a Saginaw 4 speed. I was able to use the competition plus shifter and I ordered just a rod kit from hurst/summit. It worked fine.
I recently bought the 65-66 shifter from Crash. Looks great waiting on one shifter rod and the 2223 mounting plate. Will be installing on 66 Borg T-10 to replace the factory shifter. I will let you know how it goes.
Update: Hard to find the 2138 Rod. Seems like the 2139 and 3404 are common to the Muncie trans so they are quite plentiful. Installed a Hurst Comp Plus Shifter I bought from from Crash seems to work fine on the bench.