Mercury 1990 90hp 3cyl, parts inquiry

[creol]

I just acquired this engine for $550, previous owner didn't feel like solving the issue of low RPM at WOT and I was glad to take on the challenge with that price. The engine has a nice overall look and the skeg looks like it never hit the bottom.
I took the engine home and first thing I noticed are these spark plug wires. They don't look the same in similar engines (based on googling), do they look legit to you guys? To me they look like automotive wires and even the boots aren't sitting too tightly on plugs. I'm already going to replace the boots but if the wires aren't correct ones, I will of course replace them as well. Serial of the engine is 957xxxx, made in Belgium (can't remember all the digits right now).
The other pic is of the steering arm end. I'm thinking I need a thru tilt tube steering. Does anyone have the Quicksilver part numbers for components required to assemble a thru tilt tube steering? I already know there's a retaining nut needed to attach the inner tube into the tilt tube. But what about other components?
Thanks for everyone in this community, iboats has become my first source of information on Merc issues over the last 4 years.

 

[flyingscott]

Get the right wires need to be copper core outboard wires. Before anything to a compression test and spark test. You should have everything there for the steering already has the tube. The piece laying on top will need to re-attached as that is where the arm attaches.

 

[creol]

No Title

Thanks Scott for the reply. I'll proceed as you advised. The engine seems to be running fine on the hose with no load.

Does someone know what is the thread specification for these bolts (in the pic)? It's part number 17729A 1 and I can't think of a method how to determine the thread from the bolt hole, since currently I don't have the bolts pictured, only the bracket. My metric thread bolts don't fit, even though one of them is really close. If someone knew the correct thread & bolt size, this would eliminate the need for me to drive the boat on a trailer for 100km to a special fastener shop and try out different bolts (yep, UNF and UNC are considered special in Scandinavia)... thanks in advance guys.