Hi, I realize this thread is a little old but actually just acquired an 87 Civic Si myself. You can get the rubber bushing for your transmission shift linkage from hondaautomotiveparts.com- Yep thats right, original factory parts! and they don't even cost that much! The "clevis joint" you so called described is held in by a thing called a spring clip, basically a pin you have to drive out of the shaft and the linkage pops right off you have to slide back the rubber boot back to see it which I belive has a clamp on it to hold it in place. By the way you would find this out if you picked up a repair manual, which you need for torque specs anyway ........... you are a mechanical engineer right??? I would not put any kind of tranny fluid into the transmission except Honda Manual Transmission Fluid. Also in the realm of your world ......mechanical engineer..... those gears and and that fluid is design for each other. That tranny fluid is designed to meet the force generated by that fluid, and that transmission is designed to operate within the limits of the oil. Maybe you have had better luck than I have but I have tried all different types of fluids (synthetics included) and have not found a single one that makes the transmission shift like the factory fluid does. The repair manual states that if you are not able to get the factory fluid that you can use 10w-40? temporarily until you are able to use the factory fluid. If you are having jump throttle problems you might want to check the computer which is under the passenger side seat, again in the repair book. No check engine light? Maybe someone removed the bulb or you have other issues going on, the computer should still tell you whats going on. If you need a new throttle body you can get one from hondaautomotiveparts.com or one from your local salvage U-Pull-It, some of the sensors or built into the throttle body and cannot be replaced, just might be an O2 sensor causing the problem as well. The HF tranny swap was a great idea! I loved it! But what might really boost your mileage is a swap to a 1.3L, it could be substantial! Check out this website
3g Fuel Injection Swap - Red Pepper Racing . Might have to figure out or find some smaller fuel injectors though. That sounds like it is about as far as you can go from the factory. I plan on stepping it up a notch with mine......
Propane power kits, propane conversion, small engine propane conversion kits, auto propane conversions - 3-4 Cylinder LPG Conversion Kit when I get the $850 of course. Once I convert it over it will be a gasoline/propane hybrid and I will be able to switch it to run on either one or the other at the flip of a switch, but here's the nifty trick I keep reading about, you can use that set up to run the car off of a fuel cell, or in other words a hydrogen car! Virtually no pollution! unless your car burns oil. This dude is working on it or has basically the same set up I want to put together for his dodge truck
Water for Fuel . However, with propane, I have heard that since the fuel is a dry fuel (just like hydrogen is) and is not wet like gas or diesel, I heard that it can eat up piston rings. It makes sense, but often times things that make sense are not always true. So I really don't know. The only thing with propane kits is I read somewhere if you convert it over to propane it is supposed to be certified by the EPA. If you don't want to go crazy like I am (but virtually use no gas!) you could try a hydroxybooster like the one on this site
http://smacksboosters.110mb.com/GenI_links.html . The guy used to have free plans on his site but I can't seem to find them, maybe the video is still up. Well have fun and be safe!