Will this 8 1/4" work in place of my 7 1/4"?

My local top driveline shop here in Ottawa charged me $200 to shorten, balance and install new Ujoints (included).

Call your local driveline shops and get a quote

As was mentioned, it really doesn't matter the price as it's get it done or cant drive the car.... or stuff it in as is and wreck something. lol

If your near Ottawa... http://www.malmbergtruck.com/1427-michael-st/