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The Pontiac 455 Super Duty was a re-engineered for racing version of the regular 455 Pontiac. It had a stronger block with cross webbing in the lifter valley, malliable iron four bolt mains, provisions for dry sump oiling, forged steel connecting rods, forged aluminum pistons, 80 psi oil pump, Better flowing cylinder heads with pressed in tubes sealing the intake pushrods and round exhaust ports, longer valves (inconel exhaust valves), stronger valve springs, a high flow cast iron intake manifold, high flow cast iron exhaust manifolds (same as ram air iv and 455ho) Other unique feature of 455SD was the small cam gear, larger distributor drive gear, and corresponding larger hole in the block for the distributor. The SD was origanally slated to have the ram air iv 308/320 cam but could not meet emission standards, so the smaller ram air III cam was substituted for production. The 455 SD was underrated @ 290hp, but road tests of 1973-1974 Trans Ams showed quarter mile times in the mid thirteens at 104-107 mph, indicating a true net output of more than 350HP. If it had been born a few years earlier with high compression and the larger ram air iv cam it surely would have had a 425+ gross HP rating.

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Q: What makes a 455 super duty different from a 455?
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Related questions

How can you tell if a 1973 trans am is a SD 455 or just a 455?

Typically, if it is a super duty, you'll find "455SD" decals on the shaker scoop. If yours is a high output or standard engine, it will be badged as simply 4 5 5. If you're still unsure, the super duty utilised round port cylinder heads and an LS2 intake. It also included cast iron exhaust header-manifolds.

Which motor has the most horsepower a Pontiac 455 or Buick 455?

The Pontiac 455 came in 3 versions. Base, High Output, and Super Duty. The base 1970-71 engine produced 200 hp and 455 lb/ft torque. The Super Duty 1970-71 engine had 335 hp and 480 lb/ft torque. Power was reduced after 1971. The Buick 455 came in 2 versions. The 1970 Base engine had 350 hp and 510 lb/ft torque. The Stage 1 engine had 360 hp and 510 lb/ft torque. So as you can see the Buick was the more powerful engine by far.

Is Pontiac 455 heads exchangeable with Oldsmobile 455?

No, they are completely different.

Will Oldsmobile 455 headers fit on a Buick 455?

No. they are different head designs.

Why is 1973 455 under rated what is the rating?

Which 455? Buick, Oldsmobile, Pontiac? The most powerful 1973 455 would be the Pontiac 455 Super Duty rated at 290hp @ 4000rpm. It was underrated, since factory stock examples were running 13.5-13.9 @ 103-107mph at the drags, which requires more than 290Hp. Car and Driver tested one with an automatic and it ran 13.751 @ 103.6 with a stock tires and a full tank of gas. The weight of a 1973 Pontiac Trans Am would require at least 350-375 hp to turn those numbers.

What is the hp of a 455 ci Oldsmobile 1968-69?

In 1968-69 there were 2 different 455 engines. The base 455 put out 375 h.p and the higher compression ratio engine put out 400 h.p.

How many different ways can you arrange 15 different items in groups of 3?

15C3 = 455

Will headers for a 403 Olds fit on a 455 Olds?

No, the blocks are different.

What is 29 percent of 455?

29% of 455= 29% * 455= 0.29 * 455= 131.95

What is the answer to 65 percent of 455?

65% of 455= 65% * 455= 0.65 * 455= 295.75

How much does the Husqvarna 455 Rancher chainsaw cost on average?

The Husqvarna 455 Rancher chainsaw is listed for sale all over the internet for about $329.99. The Rancher is the ideal chainsaw for a landowner who needs a high powered, heavy duty saw for all cutting conditions.

What is 455-100?

455-100 = 355