The longer ones that are recessed into the Janelle will need a spacer if you are using bolts. If using studs you can check here for reproduction hardware. Hope it helps.http://chucker54.stores.yahoo.net/oemexmastnu.html
Cant use studs and still be able to take the manifolds on and off. Just had to pull out all the studs to get the manifolds to fit in. Did everyone just bolt them in and then drop in the motor?