Re: 1992 70 H.P. Force cylinder pic (toast?)
The photo makes it really difficult to determine the of degree damage. I can see the nicks in the ports and the horizontal lines, but I can't see the condition of the cylinder below the ports and it looks suspicious.
Now: Worth repairing? Depends upon your definition, but usually yes. A boring job usually runs about 55-65 bucks a hole and pistons are about 125. You need only repair the affected cylinder.
If the cylinder liner is cracked, then new liners are available for somewhere around 100 bucks and it costs 200-300 to install them. But, a good used block could probably be scrounged up for around the same price. Unfortunately, (I think--depends upon year) the 70 uses a different front casing which incorporates the shift linkage mount so other three cylinder blocks can NOT be swapped in easily.
If the liner is not cracked, the nicks in the ports can be substantially removed by squaring the ports with a dremel and carbide bit. However, you want to do this on all three cylinders before having the bad one bored. The net effect will be a significant gain in horsepower with SLIGHTLY better mid range fuel economy. Of course, full throttle fuel economy will drop since it takes more gas to make more horsepower.
