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Trying to find the old thread

blue69runner

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When surfing found that on the motor 383 the piston should not come to the top of the cylinder and should be some gap between the piston and the top of the block. If some one could help me with that gap that is needed would be grate. Any help would be appreciated. blue.
 
There are some people that believe a 68/69 383 had pistons that were actually higher than the top (known as the deck) of the block. The clearance comes from the open chamber heads new in 68, that replaced the earlier closed chamber heads.
The lower the piston is below the deck, the less compression ratio you will have.
To really help, we need more info. What casting # heads do you have? What head gaskets? Do you have the heads off, and can you measure how far "down in the hole" the pistons are? (If you are running the correct 906 heads for a 69 roadrunner, you dont need to have the pistons down in the hole. )
 
What info are you looking for exactly?

A stock 8.5 (lower compression) piston sits about 37 thou below the deck
 
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