I have an 81 turbo with the 301 and was thinking of putting a 400 in and was wondering if the intake from the 301 would fit the 400 so I can use the turbo?

You can make more power from a well built 400 than putting any more money into the 301 turbo. That turbo setup is so marginal it's not even worth the effort to save it or the 301 engine.

H-O Racing (now H-O Enterprises) built a blow-through turbo kit for the 400- that set up easily made double the power of the factory turbo.

http://www.originalho.com/TurboForce.html

Geno