[Hot68gto]

Opinions please . All other things being equal, in a 70 GTO, how much added value does an numbers matching 455 HO car have over an numbers matching 400 car. Thank you.

[West Coast GTO]

Out of approximately 40,000 cars built, less than 5,000 were 455 cars.
When I was looking for my 70 455, I was willing to pay more($1,000) for the same car with the 400 engine.
Also, if it is the original engine, I believe those were four bolt main engines . Lots of torque with 455 but not as much horsepower as the Ram Air 3 and 4.

[724mula]

vintage appraiser will add 25% for the 455

['ol Pinion head]

Desirablity wise, would put a '70 all numbers match factory 455 automatic GTO above its twin with a base 400 automatic combo. Once one starts comparing all numbers match factory manual trans built cars, very close valuation. The only thing that would chime in the '70 455 GTO's favor, is a percentage were factory optioned with RamAir air cleaners. That option was not avail with YS or WT 400 cars. Comparing factory RAIII built cars to factory 455 cars, higher value to the RAIII car, in nearly every instance.

[Mister Pontiac]

Originally Posted by 'ol Pinion head

Desirablity wise, would put a '70 all numbers match factory 455 automatic GTO above its twin with a base 400 automatic combo. Once one starts comparing all numbers match factory manual trans built cars, very close valuation. The only thing that would chime in the '70 455 GTO's favor, is a percentage were factory optioned with RamAir air cleaners. That option was not avail with YS or WT 400 cars. Comparing factory RAIII built cars to factory 455 cars, higher value to the RAIII car, in nearly every instance.

I think you may be right OPH, yet I'm amazed by that... I would take a 455 car ANY day over a RAIII. But I may be biased as I had a 70 455/4spd car back in the 90's. Of all the ones I wish I would have never sold...

But a base 400 vs. 455? I like the 25% premium previously mentioned. I would personally see that valuation myself.

[Hot68gto]

Thank you for the replies. I'm interested in a 70, auto, with a 455 and trying to determine what a fair price would be.

[pontiacs4ever1971]

Lot of variables. My '70 455 is a #s matching close ratio 4 speed, 601 code no power steering no power brakes. It appraised for $145,000 which is crazy. It is a points judged car and has done very well.

[unruhjonny]

Originally Posted by Mister Pontiac

I think you may be right OPH, yet I'm amazed by that... I would take a 455 car ANY day over a RAIII. But I may be biased as I had a 70 455/4spd car back in the 90's. Of all the ones I wish I would have never sold...

But a base 400 vs. 455? I like the 25% premium previously mentioned. I would personally see that valuation myself.

I have a period review of the '70 GTO with a 455, and let me say, they were not pleased with the car...
Personally, I'd rather a RAIII over a 455 - but that's me.

[ANDYA]

In my opinion a 455 car is more valuable than a base 400 model, equal in value to a Ram Air III but less valuable than a Ram Air IV. All the car magazines in 1970 show the Ram Air IV a better performer than the big cube 455. But that was back then with factory stock parts and a factory tune-up. A friend of mine purchased a 70 GTO conv several years ago with a non-original 400 (I think it was a 68 400). He wanted to source the parts to make a correct appearing 1970 GTO 400 engine( #13 heads, 7040264 carb etc.). I told him you don't have the original motor anyway so why don't you build a correct appearing 455. So he searched and found all the parts to make a correct 1970 455 ( 4-bolt main YA block, #64 heads etc.). I then suggested he install Ram Air pans as that would make the car really appear cool. Today, when he goes to shows he gets a lot more looks and complements with the car as a 455 with Ram air than he ever did with a 400 and a duel snorkel. Sometimes he will park next to Ram Air III GTO's. People will look at the 400 car and then turn to him and say "WOW" a 455 conv with Ram Air! He will always admit that the car is originally a 400 car. The engine was built to appear stock by a noted Pontiac engine builder, has fantastic throttle response and makes more power than stock. I also have a 70 GTO conv but mine had the #'s matching base 400. A 70 conv is a heavy car and my friends GTO is a lot more fun to drive than mine is.

[unruhjonny]

if you're talking base 400 vs 455 with the same transmissions, I doubt anyone will argue that the 455 isn't worth more, afterall, it was an optional engine, and will bring value...

My comment was regarding the L75-455 versus the L-74-400 (Ram Air III), which were both engine options;
When comparing cars, a major value factor will be the transmission.

[scott70]

I too would pay more for a 70 455 HO car compared to a 400(except RA4). In 70 they rated the gto 455 at 360 hp but 370 in the GP. Id love to hear where they found an extra 10 hp,,,,

[scott70]

Originally Posted by 'ol Pinion head

Desirablity wise, would put a '70 all numbers match factory 455 automatic GTO above its twin with a base 400 automatic combo. Once one starts comparing all numbers match factory manual trans built cars, very close valuation. The only thing that would chime in the '70 455 GTO's favor, is a percentage were factory optioned with RamAir air cleaners. That option was not avail with YS or WT 400 cars. Comparing factory RAIII built cars to factory 455 cars, higher value to the RAIII car, in nearly every instance.

And the 455 cars came with the nicer 12 bolt rear.

[unruhjonny]

Originally Posted by scott70

... In 70 they rated the gto 455 at 360 hp but 370 in the GP. Id love to hear where they found an extra 10 hp,,,,

I believe the Grand Prix had a higher weight rating than the Tempest/Lemans/GTO = which means the GP could have higher advertised horsepower.

[scott70]

And also I believe they rated the 455 with the small valve #15 heads at 360 hp which would have had the smaller 067 or smaller cam also......

[Mister Pontiac]

Originally Posted by scott70

And also I believe they rated the 455 with the small valve #15 heads at 360 hp which would have had the smaller 067 or smaller cam also......

But the GTO had the #64 heads and was still rated @ 360HP. I think that was the question about how they “found”an 10 extra HP in the Grand Prix with the exact same engine as the GTO. I wonder myself...

[RAIVJUMB]

I think If I were in the hunt for a 70 I would place a premium on a 455 car, more so on a 4spd and yet more on a ram air car. I think you have to look at the totality of the car. For example a 455 car with auto non air peg leg vrs a more desirable ra3 stick or even base motor 4 spd car will probably be close to a wash in many cases the 4spd bringing more. That's is what keeps all this so interesting there are so many variables, I agree that typically a 455 will bring more in an apples to apples comparison.

[scott70]

Originally Posted by Mister Pontiac

But the GTO had the #64 heads and was still rated @ 360HP. I think that was the question about how they “found”an 10 extra HP in the Grand Prix with the exact same engine as the GTO. I wonder myself...

Thats what I mean,,,youve got a small valve,,possible 066 cam 455 VS a large valve 068 cam and theyre both rated at 360? Dont think so. Thats the HO in the 70 455 HO. And yes the GP had the exact same engine as the GTO,,,,I guess it could of been just because it was a bigger car they rated it 10 hp more,,,,,for some reason.

[Hot68gto]

Thank you for all the replies. It sounds like the 455 would demand a premium, but in reality, not much more than a base 400, auto. Maybe a grand or two.

[RAIVJUMB]

I would say that a 455 auto without a bunch of options that may be the case, you would be wrong for a ram air car or a 4spd.

[pontiacs4ever1971]

There was only 302 455 4 speeds made. It's gonna be a lot more $$$$$ for them.