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1970 426 HEMI Original Head Gasket Thickness

theamcguy

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Went to order a pair of new head gaskets for the HEMI and so many thickness options. Anybody know what the thickness was of the original OEM gaskets? Also how are the new composition gaskets compared to the OEM steel shim? TIA
 
Hemis are beyond my pay grade but the Mopar engine book says the O.E. gasket is 0.017"-0.020" thick
 
The 71 Factory manual claims it to be .027 compressed. They don't give a figure before being compressed.
 
When using old parts it might be best to consider the composite gaskets for better sealing, Unless head and block were surfaced milled.
 
When mine was done he calculated NOS steel shim gaskets compressed to .025
 
Just my opinion but I'm not a fan of composite gaskets for a Hemi. Would seem the inside stud/bolt would leverage the head over the fire ring and multiply the problem of distorting the valve seat.

I think Cometic is the best option, if the surfaces are machined for them.
 
My 70 hemi Factory steel shim Compresed (used) head gasket measures 0.020" thickness at the Flat shim locations & 0.026" thick at the fire-ring & other water & oil sealing locations.....That was historically referred to as the Oem factory "0.020" Steel Shim" head gasket.....A new, unused equivalent "Fel-Pro" 8088WS part measures same 0.020" shim location & 0.040" thickness at the fire-ring & other water & oil sealing locations.....
 
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