1973 472 exhaust manifold bolts ?

What length size and thread pattern are the 1973 Cadillac 472 exhaust manifold bolts? I looked around on a few forums and nothing came up. two of mine are broken off inside the head so I want to buy a full set before I try to get any others out and possibly break more. Will lowes or home depot have them in stainless?

Why did they make it impossibly to get to these bolts as well <.< I have to try and get the wheel well off and maybe the springs and shocks because all of that is right up against it to where you can't get anything but a tiny swivel type ratchet on it.
 
What length size and thread pattern are the 1973 Cadillac 472 exhaust manifold bolts? I looked around on a few forums and nothing came up. two of mine are broken off inside the head so I want to buy a full set before I try to get any others out and possibly break more. Will lowes or home depot have them in stainless?

Why did they make it impossibly to get to these bolts as well <.< I have to try and get the wheel well off and maybe the springs and shocks because all of that is right up against it to where you can't get anything but a tiny swivel type ratchet on it.

I feel your pain. I had several break off on my 73 but that is an issue beyond my expertise so off to my mechanic. I was fortunate that mine broke off on the front part of the engine.
 
I'm not sure home depot or lowes has hardened grade bolts. I would find a shop that specializes in automotive hardware. They likely know what you need or can measure one that you have removed without breaking.
 
They all have said I have to get one that is not rusted out and all of mine are real 1973 rustouts :p They didn't know the sizes and suggested I ask on forums
 
remove head

I just replaced my manifold gaskets on my 1968 75, we removed the head and took the exhust manafold donut apart that left the head with the exhaust manafold still on the head.Then we took them to a mechine shop who used a torch to heat up the ones not broken off and were able to fix the ones broken off ones
My 68 it is to close to the fender to do anything with the bolts. it cost me a head gasket and a manafold pan gasket but every thing came out quickly and install was only a few hours. I got all the gaskets and the new harden bolts from my local auto parts store We will do the same thing on the hearse this winter.
CHECK THE LIFTERS my exhaust leak was so loud that I did not hear the bad lifter till after we got everything back together and with the motor running as quiet as a mouse execpt for the tap tap tap of a bad lifter .And like Richards ambulace the pour in magic stuff is not working
 
I don't remember the size and thread count, but I did enjoy the extra work in pulling the fenders and inner fenderwells to get to the manifolds. I would suggest heating them up with a tourch to cherry red then let them cool to black then using a ball pein hammer tap them once or twice then allow to cool a bit longer and then remove them. They will be hotter than hell but they come out fairly easy and then can be replaced. I broke off three and had to dissassemble the front of the car to drill and tap them out. My friends at the Chevy Garage told me to heat them up first and I didn't have any problems in removing the passanger side manifold bolts. I hope this info may help you and save on vocabulary lessons and embarrassing you-tube videos that may distort others views of ones personality.:myopinion:
 
extra problem!

I did find out the bolts SHOULD (still waiting on verification!) be 2 1/4in long with 1in of non threaded and they are 3/8-16 thread bolts. Get Grade 8 or stainless Steel. Lowes and Ace only have 2 1/2 but other than that they are correct.

MTS has the correct ones though. Another forum told me that the 2 1/2 can be used with a spacer or washer. Now I just have to take the car appart to see if I can get the broken ones out.

Looks like the bolts on the place where the stock manifold join the pipes are rusted almost completely off!! What size bolts and what threading are they? The manifold looks okay but those two bolts are done for. They also look to be different sizes and there are two of them.
 
The manifold studs to pipes are best cut and then removed from the manifold and replaced. Don't gamble breaking the manifold trying to take the pipes apart from the manifold on the car. Cut them with a hack saw or torch..
 
Ok I got the exhaust manifold bolts and the gasket to go about taking care of the 2 broken bolts. The only problem is getting to the other bolts to take them out. Is there a trick to doing this besides using a 6 point wrench and breaking more of these buggers off? A swivel socket won't work neither will extensions.

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This is why I removed the head

That tight fit is why I just removed the head and took the head to the michine ship to replace the bolts that broke off.and have the manifold shaved. my last back two bolts had broken before I even started I don't know if the last person tried to removed them or if they go britel and just broke off on their own. Installed the manifold back on the head before installing the head
 
I ended up unbolting that triangle shaped thing and can get to the bolts now and one came loose with the impact but the others will not budge.
 
The impact gun only got one loose the rest I had to do with hand tools. I got 3 bolts out and the rest broke. The manifold is still attached somehow though. If I have to pull the head to get the manifold off are the headbolts reusable and is the gasket reusable?
 
not a expert but

I had my brother to help with the 1968 472, he is my expert but we keep track of the head bolts by making a patern out of carbard and kept track of what bolt went where and same with the lift rods. got a gasket set with two head gaskets and it came with all the gaskets for the exhast and intake manifold gasket had to order a manafold pan gasket I don't think this was more than $150.00 for the gaskets and then I had a machine shop fix the broken bolts I had a head that I tried to remove the broken off bollts while the head was still in the car and I ruin the head so I now leave it to the experts that was $100.00
 
stupid mastakes

I tried to drill out the bolts and used a ez out on them while they were in the car and it did not work then I had already drilled them. broke the ez out in one hole drilled one off center, they The machine shop want to use a torch to heat up the head to break the broken bolt loose. My head that I had them fix had ALL the bolts break off when they tried to remove the exhast manifold from the head but they were able to remove all the broken bolts execpt one they had redrill and install a new threads.
On my 68 hearse and limo I have done all the work myself to restore the cars execpt paint, transmission rebuilt and machine work, I am a plumber and I have a socket set, hammers, and pipe wrenches, when it comes to specal tools I hire specal people to use them. its cheeper in the long run
 
maybe once I am not a full time student I can afford to let someone else do it but as is I can't. I have a fair amount of tools as I used to be a part time tire/lube guy.
 
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