Welcome on the board. You really do not want to attempt this fix without removing the manifolds. If you try to fix it with the manifolds installed, you will almost certainly make the problem bigger, more expensive and more difficult to fix. It really is much easier and better to go ahead and remove the manifolds.

You're actually in a relatively favourable situation here. It's much worse when the stud breaks off in the hole. There are stepped studs available (bigger diameter on one end than the other); you could use one of those or you could put in a Heli-Coil with thread sealant and use the correct specified replacement stud. See this thread and this article.

It is very much worth your while to get the good gaskets for the manifolds-to-head and intake-to-exhaust junctions.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks for the reply Dan. I will take it apart and follow that thread to do it right. If I go to a stepped stud instead of heli-coil I would assume I have to tap for a bigger stud. Is 3/8 the next logical size?

Yeah, 3/8" coarse thread into the head, but you'd want to keep the smaller 5/16"-24 fine thread on the outside, otherwise the manifold can't move around as much as it wants to with thermal cycling and more stuff will break. At the moment I can't find a ref for the stepped thread. I know I've seen 'em, I just don't remember who makes 'em! Anyone?

(Why not just use a Heli-Coil and the correct replacement thread?)

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

I can do the heli-coil. Is this the correct size 5/16"-18 looks like part# 1185 from heli-coil for the head side?

Update: Removed intake/exhaust manifold. It was ugly, may explain why the truck is running so poorly. Numerous leaks everywhere and the exhaust was welded by previous owner. Also after reviewing the proper fastner hardware on this site I see that it was assembled with the wrong hardware and some of the studs are different length where the smooth area is, some 1/4 smooth and some 1/2 inch smooth. Need to do some more searches to come up with a parts list for all the correct fastners and see if the 3 threaded rods that mount the intake/exhaust "hot box" together can be purchased, mine are in sad shape. Placed an order with GPRS for the intake/exhaust hot box combo gasket set. Need to buy a replacement exhaust manifold and address the stripped out stud.

Is there some other source for the 2 brass plano concave washers that I need to put this together properly? Mine were non existent.

I tried the dodge dealer for brass plano washers p/n 3751637 and was told there no longer available. These are for the two end studs.

They did stock the steel cone washers 53010091 which I ordered. Also ordered new manifold and studs.

Found two brass washers in the yard. Was very lucky as there was only one slant engine there and it had what I needed. China made exhaust manifold from 1A auto arrived too. Sucessfully tapped stripped stud out so just need to assemble carefully..

Everything back together and leak tight following the installation instructions from this site! Engine runs much much better now. Funny thing was when I was disposing the shipping box from the exhaust manifold which came from http://www.1aauto.com/1A/ExhaustManifol ... 09/1071591

I found a hardware package inside the box I was not expecting. It had the two brass washers & special nuts for the ends which I made a special trip to the yard for when I had them all along. Doooo... It also included brand new triangle washers and the special center washer. None of these parts are mentioned on the website as being included FYI.