What pistons to increase CR on low compression 340?

[matt030305]

Hey all, I recently purchased a duster with a 72 low compression 340. What aftermarket pistons could I use in order to increase the 8.5 CR to around 10:1? Before I go to my machine shop, I would like to get a general idea of my options besides milling the heads, increasing stroke and whatnot. Thanks!

 

[Demonracer]

Any of the after market pistons that are flat tops with two eyebrows should get you close to the CR you are looking for.

 

[Kendog 170]

Are you balancing the motor? If not, you need to get the same weight piston.

 

[PRH]

increasing stroke

That requires specific pistons.

You really should be having this conversation with the engine shop/builder.

 

[dano]

There are a few factors other than compression height to achieve a certain compression ratio then add dynamic compression ratio. If using a stock stroke crank that is sound; Deck height, head gasket thickness, head chamber volume, valve head volume, rod length (if incorrectly sized) Piston dome and/or recess volume with compression height all can affect the static compression ratio.

Why do you want to change from 8.5:1 to 10.5:1? Is the engine disassembled? Until you open the motor, you won't know what you have to start with.