1970 455 pontiac engine

[Pfeil]

52 minutes ago, padgett said:

In 1972 4bbl Pontiac engines got steel gears. BTW in '70 Pontiac HP rwatings were pure maketting. The same engine would have different HP rating in different Car lines (F, G, A, and B bodies) and in a few cases different engines woud have the same ratings. They also played the "derater the HP so the sans-coulottes will buy the one we want them to buy. (69 Chev 290 vs 295hp, 430 vs 435 hp...)

 

BTW Pontiac kept the indian head high beam indicator for the lawyers: said it was needed to maintain the trademark.

 

I have two 455 engines that I tore down. One a 1972 and the other a 1975 and they both have a plastic coated aluminum cam gear sprocket. Both engines had never been apart and all 455 engines were 4BBL. 

 

Please give me a example on the Pontiac engine HP discrepancies on the 1970 engine. I would like to know.  

[padgett]

My 72 400-4bbl had iron gears. I never cared for strokes over 4", in 69-70 I saw many crank failures.

 

Good example is the 70 455 same engine (carb, cam, heads, etc) was 360 hp in the GTO and 370 hp in the Grand Prix or non RA 400 350 hp in GTO, 345 in Firebird (everyone bent the throttle stop).

GTO/GP 400 was also rated the same 350 hp whether automagic or 4 speed even though they had quite differernt cams (068 vs 744 AFAIR). I had a 70 GP 4-spd/AC with an open 12 bolt 3.31. We called it "asphyxiation" from the tire smoke (yes Virginia, we were doing burnouts 50 years ago, not easy on a Florida shell road with alla them fractals.

[Pfeil]

On 1/13/2020 at 10:02 AM, padgett said:

My 72 400-4bbl had iron gears. I never cared for strokes over 4", in 69-70 I saw many crank failures.

 

Good example is the 70 455 same engine (carb, cam, heads, etc) was 360 hp in the GTO and 370 hp in the Grand Prix or non RA 400 350 hp in GTO, 345 in Firebird (everyone bent the throttle stop).

GTO/GP 400 was also rated the same 350 hp whether automagic or 4 speed even though they had quite differernt cams (068 vs 744 AFAIR). I had a 70 GP 4-spd/AC with an open 12 bolt 3.31. We called it "asphyxiation" from the tire smoke (yes Virginia, we were doing burnouts 50 years ago, not easy on a Florida shell road with alla them fractals.

 

Padgett says;{Good example is the 70 455 same engine (carb, cam, heads, etc) was 360 hp in the GTO and 370 hp in the Grand Prix}

 

 Answer; In 1970 the GTO didn't come with a 360HP  the Grand Prix did. They both were available with the 370HP 455. as far as the tab on the Firebird I can see a 5 hp reduction.

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 Padgett says;{  GTO/GP 400 was also rated the same 350 hp whether automagic or 4 speed even though they had quite differernt cams (068 vs 744 AFAIR)}

 

ANSWER; The 400 used in the GTO and G/P at 350HP used the 067 cam in the GTO and the G/P used the 067 in the M/T and the 066 in the A/T.

 

THE LAST 744 cam was used in 1969 NOT 1970, and it was only used to mid year because it's couldn't meet emissions and was exchanged for the 068 with the same 366 HP. rating. It was known as the RA3

 

Edited January 15, 2020 by Pfeil (see edit history)