Not the greatest pic....
but mine is a small Sun Pro II hose clamped to the column. Can't see the clamp. as it's under the plastic covers. Actually , a tach is almost not necessary, as the engine noise / exhaust /trans, etc will pretty well tell you where you are at and when to shift. ;)
I'll try to answer this as best I can without pics....The newer roll bars 77+ have a more squared-off curve (i.e shorter radius) than the older pre-77s. This allows the catch to clear on a horizontal plane.
As for functionality, I can't see that they help much one way or the other...but...
Roll bar issue
If you have a factory roll bar for a 74, you may not be able to open the side vent windows easily. The latch will hit on the roll bar. The radius of the roll bar supports changed with the addition of the side vent windows.
When you go to replace the bolt, you might want to try an allen head cap screw, instead of the hex head. I'll bet a Bondhus type socket hex bit would allow you to get at it from an acceptable angle.
Not sure if the ones from a 60 will work. I'm about 60 miles south of you, but know Sacto well...grew up in Fair Oaks area. Let me know what the U-bolt hole spacings are c to c. Thx.
I need a set of FRONT spring plates for a 78 FJ40. The ones on my truck are peened back into the U-bolt nuts from being drug over rocks. I need to remove the plates to add caster shims. U-bolts in good condition would be a plus, as I will have to cut the ones I have off. PM me with pics...
Great write up...but...a couple of things you failed to mention. Toyota nicks you pretty good for the cabin air filter...About $38.00 at my dealer!! Since it is not too critical to the operation of the vehicle other than to keep the heater & A/C clean, I suggest blowing out the dust with...
My OEM (original one) has some wiper scratches from the PO's neglect in changing blades. Had a mobile glass co come out to my house, cut and fitted a tinted new one for $135.00 in my driveway. The original Toyota one is tinted too, BTW.