Does anyone know if there are any clearance issues when 6" rods are used in a stock Vortec block with the stock 3.48 crank and a high lift cam?  

What are you referring to as "clerance issues?" If you're speaking of connecting rod to camshaft clearance the overall length of the rod shouldn't effect this. But I hope you do realize that increasing rod length requires a reduction in piston "length." So aftermarket pistons are required with a smaller compression height or distance...  

Thanks, Yes Ill have to buy pistons for 6" rods with the Wrist pin in a higher location. I had just heard that there might be clearance issues either with the cam, if a high lift cam was used.  

There shouldn't be, especially with the stock stroke...  

Thanks. I think that thats the way were going on our build-up to free up more torque.  

Even though I should've mentioned it earlier, may I ask why you are putting 6" rods in this 350? Unless this is a very dedicated, high-effort build money could probably be spent better elsewhere. Just increasing connecting rod length in a "mild" application will net next to nothing in terms of horsepower...  

Torque not HorsePower. We were working towards a "mild" build, but it looks like heading towards a less pump gas friendly 355.  

A higher rod to stroke ratio doesn't favor torque production either. For a mild build connecting rod length just doesn't need to be increased, like I said, there's money better spent elsewhere...  

We have an LT-1 with 6" rods , but of course it has all the other necessary componants to go with the change and NO clearence problems .