Alright, quick update. in attempting to tighten the bolts yesterday I discovered 2 of them broken off in the engine block. I now have very little doubt as to what is causing my rough/high idle. Anyone out there have any tips on tapping these broken bolts out? I'm sure it's a process that requires the engine being lifted out if the jeep. If someone has done this particular procedure before or if there's a thread already on it that I could be pointed to I'd really appreciate it. Thanks!
For what it's worth, the first time I tore apart my manifold (1988) I discovered both my frontmost and rearmost bolts were snapped off. I was in a hurry, so I just shrugged and put it all back together with the rest tightened down. Ran it like that for months, and never had a high idle (mine idles low, hahah ). The next time I tore it all apart, I was doing the head gasket so I removed the head and took it into a shop to do the hot-tank/valves/crackcheck/etc. They pulled out the bolts for me. All that to be said, I wouldn't worry toooo much about the bolts, it's a common issue. Your idle is more likely to be a bad vaacum hose or usual RENIX ground type issue.
If your rearmost bolt is broken and you really are keen on drilling it out, you'd probably save yourself a lot of cussing and broken drillbits (space is tight back there) by just pulling the head out, not the whole engine. I don't know how mechanically inclined you are but pulling off the head was not particularly difficult - hardest part being lifting that heavy SOB out/in. If you have a hoist or chainfall it would be even better. As a bonus, it's a lot easier to torque the manifolds back on with the whole deal outside the jeep, and mine ran noticeably nicer after the valve job. You'll just want a new HG (I used a felpro 530-SD), new head bolts (renix era are wierd to find, I used
chbs-1128 from headbolts.com) and a manifold gasket. Might want to replace the lifters while the head is off too. Make sure you look up/ do the three-stage torque process when installing the new headbolts!
That's what you do if you suffer from Project Creep like I do :looney: Seriously though, you can probably run it with the broken bolts forever and not really worry about it.