Datsun Roadster Forum-311s.org

So I'm sure this info is here somewhere, but dang if I can find it! Everything I'm finding says just bolt in a 5 speed trans mount. I bought a 69 donor car for the trans and accessories to swap into my 66 stroker. It seems the 69 trans mount bolts in differently than the 66. But it appears that the 69 could slide far enough back into the cross member and then weld into place? Or do I modify the 66 mount? Some say lower the 66 mount, but that doesn't seem like a good solution.
I know I have to move the shifter hole, but how about the "U" shaped tunnel support? I'm thinking I should cut it out and move forward to clear the shifter and for strength? How have others done it? Thats what I'm not finding!

Be aware that there are at LEAST 3 different mounts that I have run into, and I learned the hard way. Some quick measurements will tell you what you have. That said, I do not know the idiosyncrasies of the 'pre-67.5 frames and 5-speed swaps.
viewtopic.php?p=102501#p102501 follow to the end of the thread.

Thanks notop, I did see that. Don't want to drop original mount down because of ground clearance. Looking at it more today, I don't want to weld in 69 mount, I'd never get the rubber mount in or out! Looks like I could modify the 69 mount to work with original holes on 66, not 8 but 6 bolts anyway. Better than 2! Now if anyone has a suggestion on the "U" support in tunnel it would be appreciated!

Rivnuts into the bottom of the frame and you are good to go

I thought of that spl310, but chickened out of drilling more holes in a 57 year old frame! LOL! So I took the advice of the Datsun Competition Manuel and lowered the 4 speed brace down to the top bolts and then cut the bottom off for ground clearance. But I wanted more support than 4 bolts, so I welded on tabs so I could use the original 8 bolt holes. Gonna pull body off again before I drill out mount holes 11/16" backwards and install new stroker and rebuilt 5 speed. Appears I need to move the shifter hole forward 3 and 9/16". If anyone has any thoughts on the shifter hole AND the U shaped hoop in the trans tunnel that needs to be cut out or modified, would love to hear your suggestions! Thanks all, Paul
Also a big thanks to Dave Primo for his expert advice!

That looks like an excellent solution! Great job, man.
PM

All you had to do was drop the original mount down to the bottom 4 bolts. Ground clearance really isn't an issue and if it bothered you, just trim the lower 4 bolt section off the original mount-that takes about 5 minutes with a band saw. The original mount is plenty strong.

The mount shown in the first picture is a 68-70 5speed mount. That one is a bolt-on for all 68-70 frames.

That's right JT, I bought a 69 frame with a 66 or early 67 body on it for the 5 speed. Didn't realize the different mounts until dry fitting stuff up! Stripped everything I could possibly salvage including what appears to be a non crashed rear center panel that I will be selling in near future with many other parts from the 66, and also a rebuild 4 speed that was going into my 66 stroker before I found this! Say goodbye to frame #SRL31102541 and who knows what # 66 or 67 body, or what was left of it!

I know someone who needs the front 12" or so of the r/h front inner fender if that is available.

Sorry spl310, there wasn't much that hasn't been severely affected by the rust worms! Body wise, I got a restorable hood and the doors. I was really surprised that the rear center panel was in such good shape! Good luck with your search! Paul

Finally getting rebuilt engine and rebuilt 5 speed fitted into place today! But ran into a new problem...trans mount bolts up but engine mounts don't. Just finished re-reading tech wiki and see where others had same or similar issue with engine mount holes being about a half inch forward. Seems like the answer is to elongate the trans mount holes if I'm reading everything correctly to move everything backwards? Any other suggestions? Looking at it this evening, didn't think I had enough room between x-member and case, so will revisit that tomorrow.

You read correctly. You need to slot or redrill the transmission mount holes.

I had a similar issue, and for me it was an incorrect transmission mount. I learned that there are more than one, and the correct one fixed the problem without having to slot or "waller out" (southern term) any holes.