Personally, I like to save their mouths and would rather use a stud chain on a green horse. I wrap it once or twice around the nose bad so that it does not cinch tight like a choke chain, but rather stays in place, and adds “bite” to the halter if they decide to pull.
Start with small circles, and immediately correct the horse anytime he thinks about leaving.
A rope halter is a terrific tool for a horse who bolts on the lunge line. However, truth be told, you've got more problems than that. You need to back WAY up, like he's never been touched before, and fill in the holes.
OP, sounds like this horse needs a pro, big as he is. And 8 years old and green? Yikes.
Yup, yup, yup. SOME horses will tolerate non-professional trainers and turn out semi-OK; this horse OBVIOUSLY is NOT one of them. Get him off to a trainer before he hurts someone SERIOUSLY. As it is, you're just teaching him bad habit after bad habit, on top of evasion and learning he's boss and can get away with EVERYTHING. Dangerous, dangerous, dangerous.
I wouldn't suggest a stud chain on a longe line to someone asking this question. Stud chain on a lead line to train a civilized walk maybe. A rope halter maybe. If the OP doesn't want to take baby steps a pro is in order.
"I've spent most of my life riding horses. The rest I've just wasted". - Anonymous
I had a horse very similar to this one. I did not have a trainer, bought a really green 5 year old; I did now know he was that green at the time. He could break away on the lunge line with any bit, any stud chain, and configuration of line set up imaginable any darn time he felt like it. You are just not strong enough to hold a horse that wants to go, period. Of course, while riding him, he would also buck, take off, and to whatever else he felt like doing.
Well, since there was no trainer at the barn we were at, we moved. Horse and I started taking weekly lessons from trainer at new barn. We started out pretty basic, like almost back to square one. Yes, he knew how to lunge properly before, but felt he had no reason to behave. Now he is about 6 months into just a weekly lesson and he makes NO effort to take off while lunging or act up under saddle. I really think it is two things: he has respect for me and a job that he is learning how to do--which gives him confidence in me and himself, so now there is no reason to act up. Simple. I did not have to put horse in full time training, just took a lesson once a week with a good trainer and worked hard at what she showed us until the next lesson. Yes, she hopped on him a few times during our lessons and rode him to show me what to do, she also showed me how to lunge him with a whole different attitude, but also in a much more humane/gentle way than all the bits, chains, etc... My other point is that until I learned how to do it properly, he was not going to behave for me. The horse knows who is on their back or holding the other end of the line and will act accordingly.
Now I am kicking myself about all the time I wasted not making the move a few years ago.
Get some assistance from a good trainer, you will be amazed at what even a little help can do for you and the horse. Now we are having fun, no stress, no worries and he is picking up new things amazingly fast with a happy good attitude and so am I.