I have a 72 cutlass that I put a new 12 bolt w27 rear end with disc brakes in. My 14 inch rims will not fit hit caliper. What do you think pf spacers. The new engine has a lot of hp and torque. Also the engine builder used an air gap performer manifold. Am I going to be ok with hood clearance. Drop base air cleaner and frame mounts help?

 

What are you calling a 'new' 12 bolt W27 rear end? Do you actually have a 1970 W27 aluminum differential you converted to disc brakes?? Why??? That thing is rare as can be and is worth huge $$$ as OEM.

If on the other hand you mean you have an O type rear with a W27 aluminum differential cover, why not just go with 15" wheels?