400 Spread bore intakes are nearly free.....IF you pay more than $20.00 for such an intake you paid too much. Then again the adaptor to put the t-quad on the older square flange intake is about the same amount of money.

Maybe someone would swap you your square flange intake for a spread bore intake even up....

And your trans linkage should be easy to find at a junk yard. Pretty much any 400, thermoquad engine, will have trans linkage you can make work.