I'm reading the instructions here and they're saying that I might need different sized pushrods since I'm messing with how the rockers are set up. Any validation to this?

 

You should be able to use the stock push rods. A lot of people go with chromoly push rods for extra insurance.

 

When in doubt... measure. Better safe then sorry.

 

yeah i guess. any concrete answers from experience here?

 

I have Impala head gaskets and heads milled .015" and ended up with 7.05" pushrods.
I would think you will need pushrods shorter than 7.20" but just measure to be sure.

Note that my heads have longer valves which requires the shorter pushrods, you may
be able to get by with stock length.

 

how.

 

You are changing the gasket .020 generally pushrods come in .050 increments. If the stock setup has proper geometry then the stock length will likely be closest, ONLY way to really know though will be to check it as you assemble.

I would put it together with the stock pushrods(long as rockers are SA) and see what the pattern looks like. You can drive it for a week while new pushrods come in long as it is close. Once you check with the stockers decide if it is stock lenght or slightly different you need and order them, change them the next weekend. Pushrod change is not that big a deal.

 

Oops! I always forget about the longer valves. With stock valves you may find that
the .020" difference with the thinner head gasket works with the stock length pushrods
as stated by 96capricemgr. I have longer valves which makes for the shorter pushrods.

Basically ignore my comment about the 7.05" pushrods.

 

If the impala uses a thinner head gasket, and the motors for the most part are the same, what size pushrods are in the impalas LT1?

 

7.200, it is a different head though.

 

That is true. However, I find it hard to believe that GM would use a thinner head gasket and then design the head to use the same pushrod. I am sure that GM found that the geometry (especially in a stock setup) did not change enough to force a different pushrod length. IMHO, in a mild application (stock cam), we probable have nothing to worry about with pushrods.

HOWEVER, consider the following:

GM used a thinner head gasket on the impalas. If I am not mistaken, they also used iron heads on the impala. With our iron block / aluminum head setup and the different expansion and contraction rates of the dissimilar metals, do we risk leaks or sealing issues with such a thin head gasket?

Also, (I asked this in another thread) what is the compression bump and power increase expected with this mod?

 

You might be onto something. Guys?

 

I am running 1.6 NSA rockers, Impala Head gaskets and a CC503 cam. Stock 7.2 sticks...

 

The way the stock rockers are made and operate, IMHO a little difference in deck height will not make much change in how they operate at the valve stem. The stock rockers have a broad contact surface and a slotted mounting hole-nothing like a roller rocker that has a narrow contact patch.

 

I have hardened stock length sticks, correction.

runs like crazy