I'd like to rebuild the 302 in my '79 F-150. I'm interested in rebuilding it stock, but I wanted to know what is the best piston I should put in there? What's the difference between a forged piston, a hypereutectic, and a recessed head piston?
Thanks in advanced
WrenchHead

1979 F-150 Custom. 302 V-8 4-spd 2WD. 122,875 Miles

 

Hey wrenchhead,

A forged piston is what it says. an aluminum piston that has been forged, not cast. They are better for racing than everyday driving because they withstand detonation better, nitrous, etc. They are generally a little looser fit in the bore(because of their expansion rate) and are therefore noisy until warm.

A cast piston is pored from molten aluminum.They are dimensionally stable. Almost all factory pistons are cast except hi-po applications. These are your grocery-getters. Cheap, but very reliable. May not be what you want for hot-rodding, but they are good enough for the mild bolt-ons.

A hypereutectic is a "happy medium". It is a cast piston with a high silicon content and is therefore tougher than a cast, and can be fitted in a tighter bore than a forging.

A "recessed-head" piston, as you call it, would simply refer to the valve reliefs or dish in the top of it for lower compression ratios.They vary according to what you want to run. From dished to "pop-up" which would be above the deck height of the block.

I hope this answers your questions. If I've left anything out there is plenty of top-shelf help here.

Chuck