455 1971-76

Pontiac V8 455 1971-76

Two Very Different Heads — 455 1971-76 for Pontiac V8s

The 1971-76 455 covers the low-compression years and, at its peak, the 455 Super Duty. Butler's listings put the 1971 castings such as 96, 7K3, 197 and 7F6 in a different valve length group than the 1967-70 heads, and the Super Duty 455 castings get their own parts entirely.

Butler lists a bronze valve guide set specifically for Super Duty 455 cast iron heads, at .342" ID by .564" OD by 2.280", separate from the standard Pontiac cast iron guide, along with Ferrea valves, seats, seals, springs, retainers, locks and shims.

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More About 455 1971-76

1. The Standard 1971-Up Castings

Pontiac changed heads for 1971, and the parts follow the casting number, not the year on the title.

A different valve length group	Butler lists the 1971 castings including 96, 7K3, 197 and 7F6 alongside the 4X, 6X and 5C heads on the 4.980" valve length, where the 1967-70 group uses 5.095" and 5.110".
Common sizes	Ferrea offers a 2.11" by 4.980" 30 degree intake and a 1.77" by 4.980" 45 degree exhaust for this group, listed as matched kits against those castings.
Buying spring height	Butler notes the longer 5.110" exhaust and 5.095" intake valves may be used in 4X, 6X, 96, 7K3 and 5C heads for taller spring height, but you must use a longer pushrod.

2. The Super Duty 455 Is Its Own Part Number

If you have an SD 455 head on the bench, do not order the standard cast iron parts.

Its own guide	Butler lists a bronze valve guide set specifically for Super Duty 455 cast iron heads, measured at .342" ID by .564" OD by 2.280", which is a different outside diameter and length than the guides used in a common Pontiac cast iron head.
Verify the casting	these heads are valuable and scarce. Confirm the number before anything is machined.
Call it in	a Super Duty rebuild is worth a phone conversation rather than a guess from a category page.

3. What The Low-Compression Years Need

Exhaust seats	heads from the unleaded era deserve a hard look at the exhaust seats. Your machinist decides between cutting and inserts.
Guides	11/32" cast or bronze guides for standard Pontiac cast iron heads, bronze if the engine is going to see stiff springs and a high rocker ratio.
Springs	cast iron head springs are rated around a 1.600" installed height, chosen against the cam and checked for coil bind at your lift.
Let Butler spec it	the cast iron Head Builder Kit matches valves, springs to your cam specs, chromoly retainers and locks, seals for machined guides and a shim kit to the casting you send in.

Find the casting number and tell us whether it is a standard 455 head or a Super Duty piece. Those two answers change nearly everything on the order.

Not sure what your Pontiac needs?

Call our tech team at 866-762-7527. Tell us your engine, heads, car, and power goal, and we will put the parts together as one combination that works.