[66sprint6]

I've managed to snag a pair of RA manifolds for our Round port engine. I'm not sure if they will work in our '67, but at least I can get the motor fired up on a stand.
The manifolds didn't come with any hardware, however. I've researched online and have seen that companies are selling nothing but a bunch of grade 8 bolts and charging big bucks for them. I don't know what lengths are requred (there's a few different lengths required for these RA manifolds). But if I knew how far into the block they need to go, then I could take them to the Fastenal and figure it out. So if anyone has that information that would be extremely helpful.
Also, there's no studs in the outlets either. I see some kits offer a bolt instead of the studs, but I'm wondering if that is good or bad. Are the studs readily available?

[Skip Fix]

I would think studs are pretty interchangeable if the threads are good in the manifold, I think some sell stainless studs. Maybe antiseize the threads. I'd just get whatever gasket you are going to use and measure how long the manifold+gasket is and then add 1/2-3/4" whatever depth the head threads are to it and get some at Fastenal.

[25stevem]

The shortest depth exh manifold bolt holes in the heads are the lower end ones at 1/2”.
The other ones are 3/4”
Be sure to go for lock washers when you get the hardware and factor in that length.

Note that these lower end holes break into the head bolt holes behind them so you do not want a bolt length that is too long and will not allow the head bolt to be loaded in, or have it be pushed on by the manifold bolts you use.

[JC455]

Exh. studs- go to auto parts store and grab the HELP ones w/ the brass nuts. Use some antiseize when you screw the studs in place.
Run a cleanout tap through your exh. post bolt holes, then measure how much room you have... then follow the above advice.
Also, wouldn't hurt to clearance, as needed, the exh. flange so it fits freely over the exh. studs.

[66sprint6]

Thanks so much, guys. I went online and grabbed a bunch of bolts and washers from Fastenal. I've noticed that the kits have the bolts in 1/2" increments. I found a few in a little bag that the guy gave us. They barely stick out 7/16" from the block side of the manifolds, before adding the gasket, and I just didn't that was enough. So I ordered a whole bunch of bolts, in 1/4" increments so I can pick and choose when I get them. All grade 8 bolts and the whole order came to 15.00.

[Half-Inch Stud]

Is a tradition for me to cut/grind the EXH bolt lengths to exactly what is needed.

Leak-free Head pipe fit is the tough part!

[Tim Corcoran]

Why not just go to your local ACE Hardware store and get the bolts?

[66sprint6]

I ended up getting the bolts from the fastening supplier. Everything is great. The different lengths will really help with the install.

Next question. Does it matter if I use studs or bolts to mount the RA flanges for the head pipes? I've seen a few ads for available bolts to be used with the flanges, instead of studs. Can anyone confirm? If so, what is the thread pitch and length?

[25stevem]

I have always found studs to be a whole lot easier!