heres my coolant bypass on my 1989 sohc
first of, remove the intake and hoses from bay, also get all the wires out of the way
after this romove both hoses attached to the throttle body.
#1 hose and were it was removed from
now #2 hose and were it was removed from
now after this you will have to buy or find a hose long enough to connect the two nipples to complete the bypass. neither hoses you removed are long enough.
i got a hose from my freinds intake manifold that came out of his 1993 civic. this hose happened to be an almost perfect fit but many hoses will fit.(try to get one with at least one bend or get silicone one)
here it is
and here it is once connected
now cap of the throttle body nipples and put everything back together. bleed the coolant system and take it for a drive.( some of you with bigger or fater hands, might have to remove the outlet hose for the radiator)
hope this helps someone and about gains i couldnt really tell because my exhaust is literally broke in half. but it was a fairly easy job, took me about an hour, only because i was taking my sweetass time.