can someone explain to me the difference in heads?

what was standard on a 69 cutlass?

what advantage would one gain by adding an "E" head to the original 350 engine?

 

THe E head is for a BBO You can use them but yopu would have to go with a performer rpm intake for the sbo and then do some head work or piston changes to get the compression right . Not a bolt on and go deal.

 

Small block Olds heads carry an identification number, big block heads use a letter. The big block heads have larger ports, larger valves, and usually larger combustion chambers than the small block heads. They do bolt on, however as noted above unless the engine is modified to take advantage of the big block head, you will actually hurt performance due to the compression ratio drop and the mismatch in the intake ports that will cause a flow disruption. Bolting E heads onto an otherwise stock 350 is a waste of time and money.