Installing  new AC/Heater actuator vacuum hose’s on 78. The new hoses are slightly larger O/D than originals with a larger I/D. Fitting them to the original rubber vacuum control tree is where my question begins.  Suggestions on how to splice the new hoses to the tree. Guessing the old hose is 1/16 id. New slightly larger id. I can use plastic inserts will varing size nipples on the end or cut the old hose off at the tree leaving a short piece and try sliding into the new. Checking to see what others have done to connect the hoses at the tree. Wish they sold trees that worked with the new hoses. Thanks 

Not to be a smartie, but if you go to the sites of the CORVETTE SUPPLIERS, Corvette America, Corvette Central, Volunteer Corvette, Ecklers Corvette, or others, they have the O.E.M. parts that will fit and function correctly. Over the counter parts stores won't carry the correct product. Especially in today's world where metrics are concerned. J.M.O. 

Thanks for reply. I purchased first set from Dr. Rebuild. Little larger in diameter OD and ID. Order second set from Corvette Central and exactly same. Quality hoses What I’m in process of doing is cutting old hose off of vacuum tree and leaving about one inch of old hose   That one inch slides into new hose  with some help from WD40   I apply a little weather strip adhesive first   Then I put shrink wrap over it   Dries fast and pressure  check good  

thats weird they are different size, I ordered for my 75 and they were the same size

I assume your 75 and my 78 would be the same size hose’s. The hoses I replaced were the originals.  The new ones were striped correctly and correct length. Curious how you attached your new hoses to the stock rubber hose tree. In my situation I cut the old hoses and left about one inch in the molded tree to slide the new hose over it.  The new hoses have a larger ID than old ones. I couldn’t find any jobber that carried a replacement tree.  Thanks for reply.  

I know parts stores, like O'Reilly and NAPA, sell vacuum hose adapter pieces (one size on one end and another size on the other end).  Would guess that they would also have trees with different size ends.

Thanks for reply Norsky.  That’s what I’ll do. They are in the process of building an O’Reily’s in this country town. I’ll get what I need at NAPA.