[steve25]

All of the 1970 400 motors where spec’ed with a .023” deck clearance as in this chart.

By 1970 even the RAIII manual trans cars where only fitted with the 068 cam.

[Ramairnacho]

Originally Posted by steve25

All of the 1970 400 motors where spec’ed with a .023” deck clearance as in this chart.

By 1970 even the RAIII manual trans cars where only fitted with the 068 cam.

If block.is decked like that then why do people say get deck.zeroed and a quench of about 0.40 th of an inch. Hmmm. They want an additional $250 to zero

[Will]

Originally Posted by Ramairnacho

If block.is decked like that then why do people say get deck.zeroed and a quench of about 0.40 th of an inch. Hmmm. They want an additional $250 to zero

Because engines with true zero deck run more efficiently and make better power with less chance of detonation for any given compression ratio.

Also, if I'm not mistaken, the factory head gaskets were thinner than commonly available aftermarket replacements. Even if the quench distance was a little big it was not a problem in the era of commonly available 100 octane pump gas.

If you deck your block to zero and run a Fel-Pro 1016 head gasket you'll have .038" quench distance - perfect.