I'm building up a core transmission with custom gear ratios. Most of the core trans pieces look really good, but I'm questioning the synchro assemblies; don't remember this large of a gap between brake bands and thrust blocks on previous transmissions.

Could this much gap be normal? It looks to be 1/8 - 5/32" gap on each brake band.

Thanks,
Jim

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There are different length of blocks and stops for 1st gear and early/late

I’m wondering if you have some short bands mixed in?

As far as I know, there are two versions of the 901/914 syncro blocks and bands. The earlier 901 version used longer bands and a shorter fixed block. The later version was used on the 914 and as far as I know on the 1970/71 911 transmission and 3rd through 5th gears on the 915 transmission.
The attached pictures show a 914 gear syncro on the left and a 901 syncro on the right. The approximate measurements for the short and long bands are also shown.
That said, it looks like you have too much clearance between your bands and the blocks. There should be no clearance when you push the bands against the central ring..Click to view attachment Click to view attachmentClick to view attachmentClick to view attachment[attachmentid=781
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