Hey Clair, if memory serves, you were concerned about the length of the Toyota yoke. Correct?

Reason I ask is Greg posted a clip from some other forum with an aftermarket yoke part number on slantsix.org, so I've been doing some research. Part number doesn't match with anything but I did track something down to a manufacturer in Australia (Hardy Spicer).

Long story short, it doesn't appear that the spline engagement is much shorter than a Turbo 400 yoke (per the manufacture’s info) at 4.530" vs. 4.685".

Part # posted was 3-3-3558. Best I can tell, the part # should have been 21R-3-3558, but that is for a 23 spline yoke and the R154 has a 21 spline output shaft. They show two part #'s (2R-3-3188 and 21R-3-3208) for Toyota 5 speeds with 21 splines. In theory (per the forum clip) one of these would allow a larger 1350 u-joint, but the numbers I found for the 21R stuff shows a u-joint cap diameter of 1.078" which is much smaller than 1350 u-joint cap. The 2R stuff was even smaller at 1".

Just some more info, thought I would share.