ReallyWildStuff

What is the correct part number / specification for the "exhaust studs & nuts" as for WZ manifolds?

I do see all the usual suspects selling a package of 10 bolts+washers that mount the manifolds to the block but that's NOT what I'm talking about. New WZ reproductions don't appear to come with these studs pre-installed, yet I I still could not find the studs listed at Brothers, Fusick, Supercars UL, OPGI:

two studs and two nuts per manifold
secure the exhaust system to the output end of the manifold

These are the type of item I am asking about:

http://www.oreillyauto.com/site/c/se...442&vi=5142741

thanks

68442

I don't think you will find anyone listing studs for the Olds specificly
Because they used bolts from the factory.

steverw

I believe i bought some at Advanced Auto that have the long brass nuts

joe_padavano

^^^THIS!

In any case, I wanted studs in the manifolds for my 67 Delta. I got stainless studs and nuts from Totally Stainless. They work great. The studs have coarse thread to fit the manifolds and fine thread for the nuts. The end of the stud is machined to a ball profile to make starting the nut much easier. I highly recommend these if you want studs.

Their PDF catalog is here. Studs are on pg 123.

ReallyWildStuff

OK, thanks for all of that.

The only other pair of WZs I've ever had were equipped with studs. I can't now recall what arrangement my 307-equipped cars came with. I looked this AM, the 77 403 has bolts.

The single W & Z I have now are bare. The Z has one heli-coil. They are both very tired (hairline cracks on the head side, underneath the center dividers) but will do for the moment.

Studs make it a lot easier to re-install the exhaust flanges to the manifold after a service job.

I don't know how to reconcile TS's catalog text " *USED ON MOST STOCK FOR EXHAUST MANIFOLDS* and -BOTH ENDS ARE COARSE THREAD- with JoeP's comments below re: two different pitches on a stud. Is fine thread in fact preferable for the nut side of the exhaust connection?

I don't know what size or pitch is appropriate for WZ (5/16 ? 3/8 ?) and literally no idea what length is appropriate. I'd also need matching bolts with washer flanges for the other side of the exhaust.

If bolts are in fact the stock arrangement, I'm surprised those aren't listed right next to the 10-pack of manifold-to-head bolts in the restoration catalogs - specs for a product like that would at least give me something to go on.

As I am having so much difficulty finding these answers online, I suspect I am almost certainly "doing it wrong" - but not sure of what I don't know.

1970-W30

Don't overthink this, it's not complicated. Get grade 5 or better 3/8-16 coarse thread bolts about 1-1/4" or 1- 1/2" long or (4) 3/8 studs that have at least one end coarse thread with corresponding nuts. Use never-seize on the threads and you're good to go.

joe_padavano

^^^THIS.

The threads that go into the manifold need to be coarse. The other end of the studs just needs to match the nut. There may be some technical reason for different threads on the studs (the ones in the water pump are like that) but I can't really see where it makes a difference.

ReallyWildStuff

Thank you, that was the level of specificity I was looking for. That information is not listed in the elsewheres I was searching.

So to go with TS studs, I'd select 3/8-16/24 in either 1-5/8" or 2" length.