#3 and 4 rod bearings are the weakest point in that motor, I
would suggest replacing the rod bearings if you can. The
thread size is an 11mm, probably 1.25, I had to buy a complete
jumbo set of Sears metric taps to get the right size (I needed
a set of taps anyway, you know how that goes). Any non-hardening
teflon pipe dope will work fine for sealing the bolts. Make
sure that the water pump you get has a metal impeller, the
plastic impellers fail extremely quickly in the Fiero app.

Don't dunk the throttle body, there's an O-ring inside where
the metal tube goes into the bottom of it, as well as where
the brass fittings go for the heater lines.

Use the Felpro top end set specifically for the Fiero, it
has the proper silicone valve cover gaskets. AutoZone has
the best prices on it that I've seen anywhere.

JazzMan