1997 Tib. 1.8 & 2.0 Exhaust differences
 

I've got a question for the Tiburon experts out here. I bought a 1997
Tiburon with 1.8 liter engine new, so I know that what is on the car is what
was put in by the factory. I recently purchased, through Ebay, an exhaust
manifold from a 1997 Tiburon FX (2.0 liter engine). I made this purchase
because the original manifold on my car, which is constructed of thin wall
tubing, had developed a lot of cracks ( I understand this is not an uncommon
problem) and I was seeking an economical replacement. On receiving my new
(read used) manifold, I found that it was a heavy, cast manifold, unlike the
thin-walled manifold in my car. Also, the vertical length was much shorter
( from engine flange to exhaust flange).
Okay, now to the question(s). I had always believed that the 1.8 and 2.0
engines were basically the same with bore and stroke being the primary
differences. I know the head on my car has a 1.8/2.0 designation cast into
it. Are the blocks, in fact, different?
Can I purchase a flex pipe from Hyundai that would properly connect the
cast iron manifold to my stock exhaust system, or were there other
differences in the FX exhaust system that would preclude this?
Thanks in advance for any help you provide.