yeah they are good up to a .600 lift

 

What is stock length in our trucks?
What will determine if you need longer pushrods?

 

I replaced mine just for cautionary reasons.... I also used a good set of ls6 springs... you can use 918's but there for a higher lift cam... There also alot more expensive...

 

I already have a set of 918 springs so I will be using those.How do you like the cam is it sotp feel, did you retune?

 

7.4" stock. A.M. cams have a smaller base circle. Thus stock geometry is not the same. If you mill your heads of course you will need shorter rods. I bought a set of the TR rods solely because they are a bit longer than 7.4 rods to make up for the smaller base. The LS6 springs are alot more forgiving. And they dont break like 918's.

 

how do 918's break?

 

Trust me. They do. Browse through the Internal Engine section of the board a bit. My freind has had bad luck with 918's. He had 2 break in 2 sets of springs. Valve slapped a piston, bad things happened. He wasnt even running a big cam and the springs were properly heat cycled. It looked just like they exploded. Not sure what the deal was. Changed to the Crane duals and hasnt had a problem in a year.

 

Even if you heat cycle the 918's, they will break if they are not warmed up properly. As long as you let the engine get to operating temp before gassing it, the 918's should work fine. Just make sure you're 918's have the blue stripe on them. Comp had problems with the first couple batches of 918's breaking, and I think they had the gold stripe on them. Bottom line, if you treat the springs right they will handle well.

 

Hmm Intersting I never heard that these were prone to break, Do you happen to have a part number for those springs so that I can check them out. But him having the piston slap a valve one can expect a valve spring to break cause of something like that. How did that happen, were the pusrods to long or something?

 

I think he means the piston slapped the valve, because the spring broke. Commonly known as "droping a valve". And he's right, more bad things happen when that happens.