077 valve springs

[70gtx]

when installing p2806077 double valvesprings is there any machining needed on the stock 440 heads.on the seal area or spring seat area?

[DartGT66]

You have to machine the head, the valve spring seat has to be machined flat, also you have to machine the valve guide to accept a smaller diameter valve seal, I would also check the clearance between the retainer and guide at the lift of your cam and have the guide shortened. Usually this has to be done with about over .53" lift.