The ones you're looking at would most likely fit.
Look up shocks for a Honda Z50 they are the same or about the same size as the earlier C70 Passports
I bought the red 265mm Kitaco shocks from http://www.hondaminitrail.com/z50.html which are about the same price you are looking at and seem a bit higher quality. They took a few weeks to come because they had to be special ordered but definitely worth it and MUCH better than the original shocks on my '80 Passport
Oh, and FYI the rubber dampers might not be the same size. If I remember correctly the dampers to fit around the bolt up at the seat were a larger diameter than the bottom. So for the shocks I bought the bottom was fine, but I had to replace the top damper with the damper from the original C70 shock. Took a little work to get it in there but not too complicated once I figured it out...
I would say a rear shock replacement is well worth it. Especially if you're riding with passengers every so often
--- In Honda-C70@yahoogroups.com, "jonyoon" <jonathan.yoon@...> wrote:
> What are the dimensions of an 81 C70 Passport rear shock absorbers? I've been having some rough rides and am looking into replacing my shocks.
> Do you guys think these will fit well?
> or this (same but cheaper)
1970-73 C70 Honda Service Manual: http://tinyurl.com/6ebwtw
1970-73 C70 Troubleshooting Guide:
http://tinyurl.com/6ebwtw (scroll to sec.7.1 page 101.jpg)
1980-83 C70 Honda Service Manual: http://tinyurl.com/hu42c
1980-81 C70 Troubleshooting Guide:
http://tinyurl.com/hu42c (scroll to sec.18-1 page 170.jpg)
1982-83 C70 Troubleshooting Guide:
http://tinyurl.com/hu42c (scroll to sec. 20-28 page 205.jpg)
1980-81 C70 Maintenance Schedule: http://tinyurl.com/z4zn6
1982-83 C70 Maintenance Schedule: http://tinyurl.com/hw35c
More resources for C70 Passports and Cubs: