Here’s my install. Plenty of clearance except inboard on #1. There I used a regular header bolt with stand alone Nord-Lock washers.

 

And if these were aluminum heads I’d probably use studs. This is an L71.

 

Before everyone gets carried away with header studs. We are only talking about 25 ft lbs or so of torque.
The same torque specs as what the Intake bolts get, going into that same aluminum head. (but w/o the stress of the exhaust weight)

A drawback of header studs is you have to have the clearance room past the stud to remove the header. Not always an option.

 

How hot do the intake bolts get? Aluminum intake, aluminum heads, no problem!

I had a 17% failure rate of OEM GM exhaust bolts in (stock) aluminum heads. It was really a chore to remove them, too. It required a welder. It's not just the initial torque that matters, but the constant heat cycling. So studs are "better", since they are torqued with the head threads static, but you need to be able to get them to fit, too.

 

I tried the stage 8 bolts and always had gasket blow outs and a small rotation or heat expansion of the bolt just enough to cause problems. Then I went to bigger 1 3/4 headers and the capture where the collar did NOT work. I've studded everything since and have 172,000 miles with all kinds of engines since without a failure with just a dab of red silicone.

You don't want to strip out the heads exhaust holes!

 

Ok guys, this is what I did.
Today I ordered this ARP header stud set and this ARP header bolt kit from Summit Racing.
Once I receive them I will see if I can use the studs first.
If I can’t, I’ll install the headers with the bolts.
I’ll let you know what I ended up using and let you know why.
Should I use anti seize on the chrome moly studs, since they are going into aluminum heads?

 

I just safety wire mine (old aircraft mechanic) and use anti-seize. They've never come out unless I want them to.

 

i have used ARP studs and the nuts would never stay tight...whatever you use you will need a lock on it. Ive used allen head bolts that were drilled for aircraft wire locks and Ive used a stage 8 version as well...the locks never loosened up so they couldnt blow out. Now I use Remflex exhaust Header gaskets and the the stage 8 header locks that have the longer locks and the 12 point lock so it can be clocked without overtightening the bolt https://www.summitracing.com/parts/stg-8912a...never an issue

 

Today was not a good one.
I received the new bolt and stud kits from Summit.
Got my new Hedman headers, PN 68096, off the shelf and tried to install the drivers side first.
Nope, not happening, it doesn’t come close to fitting.
The second tube hits the oem steering box, and not just a little.
The front tube also hits the frame where the engine mount is bolted in.
In the picture you can see that the header flange needs to rotate out along the bottom edge to be flush with the head but it can’t due to the interference with the steering box.
At first I thought, ok I might need to dimple the tubes, but no way, they should clear the frame and oem steering box.

I thought just for the sake of trying I would attempt to install the passenger side.
Nope, doesn’t fit either.
You can also see that the header needs to rotate out for the flange to lay flat on the head, but the header tube hits the inside of the frame rail so it can’t.

At this point I’m wondering if the Moroso solid engine mounts cause the engine to sit slightly lower in the frame causing the interference.

What do you guys think?
Are any of you running the solid Moroso mounts and have you noticed the engine sitting lower or had any header fitment issues?
I’m going to start a new thread on this subject.

Anyway, the headers are all boxed up and going back to Summit.
I’m going to order a set of Hooker Super Comps and hope they fit.

To help answer the question of this thread,
If I install studs into the head, I would need to install the studs after the header was in place.
There is absolutely no room the install the studs first.
If I needed to remove the header or replace the gasket, all the studs would need to be removed from the head before the gasket could be replaced or before the header could be removed.
So I will be using the ARP bolts and returning the stud kit.

 

I have a spacer that was left over from a pair of Energy suspension motor mounts. The small block engines didnt need them with the solid motor mounts but the big block didnt line up perfectly. with these spacers they were perfect...I think that they must have had them just for a big block application as they are the same mount small or big. Some one else posted a big block mounting issue not too long ago


just a stock photo to see the spacer


you could either manufacture a plate from flat stock or test your theory with a few stacked washers to see if it would relieve the issue....

As an aside, are your heads aftermarkewt aluminum and do they have raised ports?

 

Thanks Rescue,
Those Energy Suspension mounts look taller than my solid Moroso.
Did you notice any difference between the two when you went to the solids?
Moroso makes a spacer kit that comes with 1/16”, 1/8” and 3/16” spacers.
My Edelbrock heads do not have raised ports.
Ignatz, responded yesterday and he suggested that since I received the wrong transmission crossmember, from GForce, that the engine may be sitting at the incorrect angle, and that could be causing an issue as well.
I know the engine angle and transmission mounts are wrong.
My new crossmember will be here Tuesday so once I get that bolted in correctly I’ll try these headers again.

 

Thats a stock pic for reference for the spacer only just so you know what they looked like...I dont know what the stupid AI pulled up for model, the search functions are garbage now that AI is involved. Lucky I got a pic at all.

Once you get the correct crossmember just use washers as shims behind the motor mounts until it fits correctly, then order the Moroso spacers. I would think the 1/8th-3/16th is what you will end up with.

 

It's not obvious to find on their site, so I'll include links. Moroso sells 3 sizes of motor mounts, short, standard, and long, plus shims. BBC and SBC mounts are the same.

https://www.moroso.com/catalogsearch...q=motor+mounts
https://www.moroso.com/chevrolet-motor-mounts62500/
https://www.moroso.com/chevrolet-motor-mounts62530/
https://www.moroso.com/chevrolet-motor-mounts62510/
https://www.moroso.com/motor-mount-shim-kit62535/

Depending on how/when you purchased yours, you may have a different length than you expect.

 

I didnt realize they sold so many versions...the shim kit is nice too

 

Thanks!
I looked at all these when I ordered mine.
There is a big difference in the height, but also the width dimension is only 2 3/8” and our frame horns are 2 5/8” wide, so the others won’t work with our frames.
The PN: 62530’s are the correct size and the only ones that fit.

If I need to shim them, I’ll do it with some washers first then install the correct shim plate if needed.

 

Chevy AIM or suppliers mention V-shaped motor mount spacers for BBC. But I do not know if it was for all or just AC cars.
Paragon Shims

Don't you have Edelbrock heads?
IIRC they have several versions, some may have raised ports.

I researched the Hedmans before, and some apparently fit C3 BBC with zero mods, and most cars need a small "flat spot" (1/8' deep?) at the steering box and the idler arm bolt, or that bolt/nut turned around. Either way it does not sound drastic like yours.

Maybe "up" is the answer!

 

I ordered the shims this morning and I’ll receive them tomorrow.
I’ll try the shims and if there are still fitment issues I’ll take them to my engine builder and see what he recommends to use to best dimple them.
I don’t want to hammer them, that’s just not my way to do things.

 

I picked up some 1/8” thick grade 8 washers from Ace Hardware and I’ll use those to raise the engine and add another 1/16” grade 8 washer if I need more.
If that does the trick I’ll be very happy.

 

I'm wondering if edelbrock heads place the headers in a different position than other BBC heads? Both of my motors SBC though have .600 raised exhaust ports. That is a substantial amount compared to 1/8 inch spacers

 

I have the Edelbrock Performer RPM heads.
They are advertised as having stock exhaust port location.
If the exhaust ports were raised, it would probably eliminate all the clearance issues I’m having.