Exhaust Manifold Bolt Size?

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Author Message   JEEPETR (Jeepetr) New Member Username: Jeepetr Post Number: 13 Registered: 02-2003 Posted on Thursday, July 10, 2003 - 11:17 am:    Hey All, My '96 Discovery had decided to evict one of its exhaust manifold bolts, with a resulting leak and ticking noise. Is this a standard size bolt that I can source from a hardware or auto parts store, or something specialty? Anyone know what size it is by chance? Thanx..   Paul T. Schram (Paulschram) Senior Member Username: Paulschram Post Number: 1800 Registered: 02-2002 Posted on Thursday, July 10, 2003 - 11:40 am:    8X1.25   JEEPETR (Jeepetr) New Member Username: Jeepetr Post Number: 14 Registered: 02-2003 Posted on Friday, July 11, 2003 - 09:24 am:    Hey Paul, Thanx for the Information, but I am now confused. I had put a call into the local dealer to see if by chance they had one in stock, but they didn't (no suprise there), but the parts guy said it came up in the computer as a "3/8 by 1.125". So I pulled up a metric/std. bolt chart (http://euler9.tripod.com/bolt-database/23.html) and the metric "8" is considerably smaller than the standard 3/8 (.375). Am I missing something? Thanx...   Paul T. Schram (Paulschram) Senior Member Username: Paulschram Post Number: 1816 Registered: 02-2002 Posted on Friday, July 11, 2003 - 09:32 am:    Are you referring to the bolt that goes into the head, or the one that goes into the y-pipe flange? The cylinder head is threaded to accept a 3/8-16 X 1.125" bolt. The y-pipe flange is threaded to accept an 8 m/m stud. For future reference, 8 m/m is nearly identical to 5/16 hardware Sorry to have misled you, however, it is far more common for a Rover to decide to part company with the y-pipe flange nuts than the manifold bolts.   JEEPETR (Jeepetr) New Member Username: Jeepetr Post Number: 15 Registered: 02-2003 Posted on Friday, July 11, 2003 - 11:47 am:    Hey Paul, Yes, it is the bolt into the head. Sorry about the confusion, and thanx for your responses. I'll try to pick one up at the harware store on the way home, maybe a 3/8" x 1.25" with a washer and lockwasher? Thanx again...   Paul T. Schram (Paulschram) Senior Member Username: Paulschram Post Number: 1822 Registered: 02-2002 Posted on Friday, July 11, 2003 - 11:52 am:    Expect to find that the hole does not line up very well. The manifolds tend to get distorted making it easy to pull the threads from the head if you're not careful. If the bolt won't go in easily, you're gonna have to pull the manifold and file the holes larger.