I thought I would start a thread on tips on what everyone is using for exhaust manifold bolts. Not wanting to use hardware store type bolts that fall out and also wanting to stay original finding a source is not easy. The Buicks also unfortunately used about 5 different sizes at least on a 455 including one rediculously long bolt. The Ford Ramp-Lok bolts look very close but they do not have the bare end that the Buicks had. I am not sure if Buick used same manufacturer or not or what the head marking were as they are always rusted beyond recognition in this neck of the woods. If you search the Ford sites you can find some sets for Falcons and Mustangs that have different sizes but you may need to buy several kits to get all you need. The www.Falconparts.com kit #code-3476 looks like they have some long ones in them. I did a search and tried to find manufacturer as the Ford guys say they get them from original manufacturer. I could not find them. www.AMKproducts.com did sell some sizes individually but they have changed their online catalog which is under construction so they do not list now. I will measure all my originals and list them later with numbers of each used on a 455 if anyone is interested to have a reference. Was talk a while back about someone making these but guess maybe a dead deal?
I remember that Then and Now restorations was planning on doing some of the "correct" reproduction exhaust manifold bolts awhile back but have not theard anything about it lately. I tried to send them an email but it got kicked back. Still have to wait I guess.
in the HELP section at autozone I found a package of exhaust manifold bolts and it said for all GM from the 70's to the 80's. Cant remember exact dates, but they were the type found originally that bolt on the manifold and still have a treaded section to bolt on the heat sheild. I havent tried them yet (or even opened the package) because I havnt done my header - back to - manifold swap yet. time keeps on slippin....
Curtis the Ford ramplocks are the same head and the threads are the same except for the tapered tip. They have a built in lock washer. Look at the pics at www.amkproducts.com
Only problem Jim is finding all correct sizes. AMK does not have them all and their new website does not show them.
No sweat except for the long one. We made set from their stock for the concours GSX and the concours triple black stage 1 convert.
That sounds promising. Check out www.falconparts.com part code-3476. Some of those long bolts look pretty close. I emailed them to find out lenght but they have not gotten back to me. Proabably will not. You know those Ford guys.
Me and friend purchased all the bolts we needed from AMK's selection except for the 4 incher. The AMK's are as close as you are going to get I have found. As for finding the 4 incher, cut the head off in the middle portion of the bolt of one of the longer AMK's and TIG weld it to the threads of a grade eight bolt. You will then have a strong 4 inch bolt and more importantly it will have the correct style head and lockwasher. The exhaust manifold bolts torque to 18 ft. lbs so you will not have any issues. I was amazed when I saw this could done, :shock: but it does not take much!!
Here are the AMK part #'s and quantity for one set: B-12464 x 1 (1 1/8") B-12465 x 5 (1 5/16") B-12466 x 5 (1 5/8") B-12469 x 2 (2 5/8") Note: Some manifolds require different length bolts - these #'s are for 1970 455 manifolds. AMK only sells them in packages of 4, so you will have some left over (unless you buy 5 packages of B-12465 and B-12466, then you can make 4 complete sets). Jeff - Did you make me any extra 4" bolts with the left overs?
Here are the measurements with picture of originals if it comes out. Most of the bolts had a non threaded nub that was about 3/16"
James - I am working on some extras. Had to make sure it would work on my car before I went further with the experiment. Very glad you posted those AMK part numbers, I am sure everyone will find the info very useful.
Jmaes, I get a count of 3 on the 2 5/8 size. One on the drivers side and 2 on the pass. No way shorter would work.
Dave, My casting #'s are: 1233899 LH/Drivers side - uses one 2 5/8" bolt in the bottom center location 1383648 RH/Passenger side - uses only one 2 5/8" bolt in the bottom center location. What are your casting #'s? I'm guessing your RH casting # is different, and that cylinder # 2 is where your longer bolt went. I also have some originals I can take pics of next to the AMK bolts if interested. You are correct, the tips are not like the originals, but can only be seen on the top row of bolts once installed. It's the only after market bolt that is even close to our originals. As Jeff said, there currently is no 4" bolt available, so keep yours in case you need it again.
I will have to double check my manifolds but all of them are off 70-74 engines which should all bee the same. Pretty strange.
Here is the head of the longest one above: The discoloration is corrosion on the finish of a 40 year old NOS bolt. Imagine if it has ever been used! Notce that the short length bolts above do not have taper.
Wow, that is good news Jim..... As far as the exhaust mainimold #s James gave above my info shows the correct casting numbers for a 70-74 455 are 1233451-L 1238094-R The listing James showed of 1383648-R is for a 68 Big block and the 1233899 is a mystery to me. I guess the numbers of particular bolts are year and manifold specific. So applications should be double checked.
