Are you talking about the bolts that hold the exhaust manifold on, or the nuts that hold other things like the dipstick tube to the manifold. The bolts are 8x125x35, I think, just tried to measure one I had laying around. My were a specialized bolt that had a built in lock washer, maybe only possible to find new ones at the dealership. If your just looking for the nuts then 8x125 should work.