will the lt1 factory roller lifters fit the older type 400 ci engine,,i notice the advertisment says will fit roller blocks,,,and efi ,,,,fuel injected engines,,,,,i have a 1972 400 i intend using a new cam in,will i need anything else besides the factory roller lifters,,, i will be using vortec heads,,,,

 

They won't work. There is nothing to keep them straight on the
cam lobe. You need aftermarket rollers with the bars that hook
the lifters together and keeps them from turning in the bores.

 

yeh thought so ,,,i have seen them coupled together,,,,just thought gm might have kept the internals the same like the early engines ,,lifters,,cams, pushrods,, these newer type engins are not interchangable,,,toooo many different bits,,,,