I bought a 427 about 2 years ago that was already built. It's a 99 ls1 block that was dry sleeved. I noticed however that it won't take a stock crank bolt. It had a bolt in it when I got it, and you could see someone had turned it down about 3/4-1" shorter than stock. If you try to put a stock length bolt in. It bottoms out before it hits the crank pulley. I'm just trying to find out what crank I May have. Any info or help is appreciated. I've done a lot of searching online about it with not 1 mention of anyone with a similar thing.

 

Perhaps an inexperienced builder tried to pull the balancer on with the bolt and jagged the threads up. Either a shallow thread insert or a heli-coil that still has the installation tab on the bottom of it. Just spit ballin' here, can you see inside the snout ??

 

I'm 99 percent sure ther was no work on the snout of the crank. It's been a while since I looked at it but I'm pretty sure there wasn't any thread inserts or what looked like thread repair etc. I'm pretty familiar with helicoil/time serts etc. I work for btw, and a few of our engines are famous for pulling head studs out. I'm going to pull the motor down and refresh it. Il check then. Was just hoping some old timer in the ls1 game had heard of it. I mean. Sleeving an ls1 block seemed to me Like something guys woulda done years ago. Not so much recently

 

It sounds more like you have the wrong length bolt, maybe from an LS7 which is longer.

What balancer is on there now and how much difference is there between the face of the snout and the face of the balancer hub where the bolt head sits?

 

An ls7 bolt would be about 2" too long. A ls1 bolt is already too long. I'm running a durabond underdrive. I don't know exactly the measurement between the crank/pulley but it is less than 1/8" from memory.

 

Then the snout itself should be the right length if there's about an 1/8" there. The threads may not been tapped deep enough or they're damaged. Is there another crank you have access to to compare how deep the bolt hole is?