What about using a gasket that was on the motor with the other heads they was torqued down but the engine was never fired up, so should they be ok to reuse with the J heads. The one that is on the car and leaking is : Brand Fel-Pro
Manufacturer's Part Number Q1008
Part Type Head Gaskets
Product Line Fel-Pro Performance Head Gaskets
Summit Racing Part Number FEL-1008
UPC 084113010088

Bore (in) 4.180 in.
Bore (mm) 106.172mm
Gasket Material Steel core laminate
Compressed Thickness (in) 0.039 in.
Compressed Volume (cc) 8.900cc
Lock Wire No
Quantity Sold individually.
Notes Pre-flattened steel wire ring.
And the other one I took off is:Mr. Gasket Ultra-Seal Head Gaskets
Summit Racing Part Number MRG-5805G
UPC 084041023020

Bore (in) 4.140 in.
Bore (mm) 105.156mm
Gasket Material Steel core laminate
Compressed Thickness (in) 0.038 in.
Compressed Volume (cc) 8.382cc
Lock Wire No
Quantity Sold individually.,
So the one on the motor has a compressed thickness of 0.039 in and the one i want to reuse has 0.038 in and I'm not sure if this will cause a compression imbalance enough to hurt anything.