Well MOST evo 8 turbo's are 9.8 hot side the 9's like you mentioned have the 10.5 hotside which is what most evo8 turbo owners upgrade to. Thae actual turbo is a Big 16g that's both 8 and 9. either one will work but if you can get the 9 w/ the 10.5 hot sid eyou will be able to spool it a couple hundred RPM's quiker