Hey all
Found my exhaust leak today, the driver side manifold studs are both broken. The bolts in the front flange are ok but the rear studs are gone. One stud gone also on the passenger side.

If anyone has the OE part numbers for the studs, washers and bolt or the part number for a Dorman (or other maker) repair kit please let me know.

Thanks
Steve

 

When mine failed, I took a caliper, measured how deep the hole in the block was, measured how thick the exhaust manifold was, and got a set of studs that were 1/2" longer (to give me enough for the nut on the outside!)

My 1988 with the LA 3.9 used 5/16-18 studs.

THAT said - ARP has some "header studs" that are extra long (for headers) for small block Mopars; they should fit and work. DO verify thread diameter and pitch, though; the Magnums may be metric, not SAE thread.

Can't help much past that.

RwP

 

I got mine for my 94 3.9 from the dealer. Including the cone washers. The replacements come with the block side a half inch longer in case you bung up the front threads getting the old one out. The hole is .5" deeper than the studs that came with stock.

 

Thanks guys, can't seem to find anything online that references them so I'll just go with the dealer on these. I was surprised to see them broken, is this a common failure point on the 3.9? I will admit that the bolts don't look very good either, probably should just replace all of these on both sides. Going to see if I can get by with just doing the driver side this year though, lots of other things to fix on this and manifold studs was something not on the list of fixes.

Steve

 

/me slaps himself in the head

/me checks the 87-89 parts list PDF from the FAQ

Well, for my 1988, it says (part number, quantity, and size where noted: )

6033 140 x 1
6029 832 x 2
9421 360 x 1 5/16 x 2.125
6030 622 x 1 5/16 x 2.9375
6028 355 x 2 5/16 x 1.875
6033 141 x 1 #10-16 x 1/2

RwP