I'm looking to put a tri power off a 1966 on a 68 400 block. Will this work ? Then the next question would be where do I find the intake and carbs?  Something I wouldn't have to sell my house to buy.  

"Something I wouldn't have to sell my house to buy."

That's pretty much the problem.  

Tri-Power on a 68 400 fits.  Power-wise, the 68 QJet with cast iron intake will out perform the Tri-power.  Unless you MUST HAVE the Tri-Power for some reason, a better choice for performance is a QJet on a PPR Crosswind or Edelbrock RPM.

Otherwise, bring your (fat) wallet.  

Theres a company that sells reproductions on ebay for not much more than a regular 4bbl intake.  and theres usually some actually cheaper used intakes on for cheaper.

heres the link http://cgi.ebay.com/ebaymotors/1966-GTO-TRI-POWER-INTAKE-MANIFOLD-NEW_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c39Q3a1Q7c66Q3a2Q7c65Q3a12Q7c240Q3a1318QQ_trksidZp3286Q2ec0Q2em14QQhashZitem330272231778QQitemZ330272231778  

zeus8807: that's good news that somebody is repopping the trip manifold.  Apparently you still have to get the carbs, fuel lines, linkage, etc.  

That does not change the fact that the QJet cast iron intake will outrun a Tri-Power setup.  Can't beat the latter for looks at the car show though.

Pick your poison and bring your wallet.