OK, I need help with something...........

[1970Bluel78]

A good friend purchased a 1974 SD 455 new and still has it...HP ( net )rating of 290. The 73 was 310. Car is Quick! AS I recall on radials at E town he went mid 13's

[Xplantdad]

Thanks to Wikipedia...

[ QUOTE ]
In 1973 and 1974, a special version of the 455, called the SD-455, was offered.

The SD-455 used the left over components from Pontiac's 366 NASCAR engine and was built as a full bore racing engine producing over 540 horsepower and was then toned down to appease the EPA and to meet GM's strict horsepower policy which required all GM vehicles to hold the HP to under 300. As a result, the PMD engineers listed the SD-455 at 290 HP but in reality, was producing in final form, 371 HP SAE NET (Approx 440 gross horsepower).

What made this engine unique was the ease with which it could be returned to its 500+ horsepower form. The SD-455 is often considered the last of the true musclecar motors and by many, considered to be the most powerful factory Pontiac engine ever produced.

[/ QUOTE ]

All this with an 8.4:1 compression ratio...

[akcamaro]

That makes me all warm and fuzzy inside. Now I want one even more.