Hello all,
First time posting in while and mainly looking to see if anyone has had similar issues. I have a Dart Iron LS Next Skirted 23 Bolt block with a set of Dart Pro-1 280cc heads. I am to the point of installing heads but have been battling head stud issues. There are some attached photos that show some of the fitment issues. Basically all of my 7/16" studs are too long leaving quite a few threads exposed with the stud bottomed and the 3/8" studs on the out edge were way too short when bottomed. I've been back and forth with Dart and ARP about these issues. Dart says its normal fitment on the 7/16" studs and just to install a ball bearing under the 3/8" studs to make up the height. ARP doesn't like how the treads were exposed but they didn't have much to offer other than to go by what Dart recommended. In the last picture I have a 9/32 Ball bearing under the 3/8" stud leaving me about .040" shy of the treads being flush with the top of the nut. Been a frustrating project and mainly looking to see what experiences others have had with Dart LS Block and Head stud fitment. Surely I am not the only one to have fitment issues.

 

If I were building this, I’d cut .200-.250 off the BOTTOM of the 7/16 studs…or whatever it takes to get the stud to protrude from the top of the bolt slightly, with a steel washer under it. I’d like to see a thinner washer under the 3/8 studs to get that stud up out of the bolt a tad, but if it’s out too far, I’ve seen header tube clearance issues with the stud heads. The ball bearing under the stud is not a problem, especially since this is an iron block.
I’ve bought specific length studs from ARP for situations like this. They don’t come in kits…usually in sets of 5…and cost more, but you can get exactly the length you need within reason. Mock up your headers to make sure you’re ok there, before it gets in the chassis. Much easier to make changes now vs later.

 

My studs look the same as in a little too long but I didn’t have any issues on the heads install. My 3/8” studs seem to be a good length. The only issue I ran into is I had to grind a flat spot on the washers that go where the lifters are but wasn’t a big deal at all. Also had to buy a torque adapter to get that nut torqued correctly.

 

On the top five of the 8mm bolts/studs (they are in the valley area) ARP sells the studs for the LS1-6 motors. Those studs are about .170 longer and are perfect for the thicker deck surface of say a Brodix head.