The one from the air filter to the compressor on an 89 w/garret turbo is more expensive than the ones for the mitsubishi. Still, it sounds more like inadequate boost rather than air leaks (are you getting a lot of black smoke on acceleration...if so, keep looking for the air leak(s), try the compressor bypass valve, check før bad hose or loose bolts) so check the actual boost getting to the manifold...get a vacuum/pressure gauge. They're cheap enough and usually go to 5-10psi...they're more for old style fuel pressure testing than boost testing but will work to 5-10 psi. You should have at least 7.5psi....up to 9-10 generally won't hurt. You can adjust the boost pressure by adjusting the wastegate rod length.