Brian, I believe you want this one:
RV-8, crossover, IO-360M1B 180hp w/Muff
Part Number = EA EXH 8 IO-360M1B
Price = $985.00
I have a Mattituck, TMX - IO-360 A-1A with Silverhawk EX (Bendix copy) fuel injector. Vertical Draft, stock Lyc sump. 180hp with standard 8.5 to 1 compresson. The Vetterman exhaust is first rate stuff, bolts on, no issues, his exhaust is a work of art. The above part # is what I used.