[Rocky Rotella]

Guys,

I am aware that 345 hp is the accepted rating for the WT-coded 400 in the '70-1/2 GT-37 as opposed to 350 hp in the GTO, but I'm trying to find that stated in a Pontiac-printed source. Has anyone seen one?

Thanks!

[SD455DJ]

Rocky, I've only seen the 330 hp 400 4-bbl listed for both auto and manual in the Pontiac Dealer/sales letters that are on GT-37.org. I've only seen the 345 hp number in discussions and always wondered where that came from too.

Sorry I couldn't shed official light on this for you, but maybe BVZ, OPH, or Ransom may know something.

Dennis

[Rocky Rotella]

Originally Posted by SD455DJ

Rocky, I've only seen the 330 hp 400 4-bbl listed for both auto and manual in the Pontiac Dealer/sales letters that are on GT-37.org. I've only seen the 345 hp number in discussions and always wondered where that came from too.

Sorry I couldn't shed official light on this for you, but maybe BVZ, OPH, or Ransom may know something.

Dennis

Thanks, Dennis. I have the bulletin that denote when the 400 is equipped with a 3-speed or 4-speed manual transmission, the GT-37 drive line mirrors the GTO's. Why it would be rated lesser doesn't make sense to me. I'm really hoping to find something concrete.

[SD455DJ]

Originally Posted by Rocky Rotella

Thanks, Dennis. I have the bulletin that denote when the 400 is equipped with a 3-speed or 4-speed manual transmission, the GT-37 drive line mirrors the GTO's. Why it would be rated lesser doesn't make sense to me. I'm really hoping to find something concrete.

Rocky, I think the 330 (345) hp rating was to keep the non-GTO power above the weight ratio to 10 lbs/hp max for insurance and NHRA class advantages. The 70 GTO was never lighter than 3700 lbs stripped, so even with the RAIV's 370 hp, it was no less than the 10 lbs/hp PMD seemed to ascribe to in those days. A stripper Tempest 2-dr post coupe could weigh almost 300 lbs less than the GTO, so 345 became the WT hp number based on the 10 lb rule.

Dennis

[68bird400HO]

Originally Posted by SD455DJ

Rocky, I think the 330 (345) hp rating was to keep the non-GTO power above the weight ratio to 10 lbs/hp max for insurance and NHRA class advantages. The 70 GTO was never lighter than 3700 lbs stripped, so even with the RAIV's 370 hp, it was no less than the 10 lbs/hp PMD seemed to ascribe to in those days. A stripper Tempest 2-dr post coupe could weigh almost 300 lbs less than the GTO, so 345 became the WT hp number based on the 10 lb rule.

Dennis

Can you verify where they find 300lbs to remove from these cars? I think it was brought up before that this figure was based on the AMA specifications, however, which listed T37 weight the with 6 cylinder. I am just not seeing 300lbs in sound deadener and bucket seats vs bench.

[SD455DJ]

Originally Posted by 68bird400HO

Can you verify where they find 300lbs to remove from these cars? I think it was brought up before that this figure was based on the AMA specifications, however, which listed T37 weight the with 6 cylinder. I am just not seeing 300lbs in sound deadener and bucket seats vs bench.

68bird400HO,

Here is from my Tempest thread in this section...

"The previous owner weighed the Tempest the one time he had it at the track and it weighed 3650 lbs with him in it and a half tank of gas....he weighs at least 225 lbs, and I'm at 150 lbs, so 3575 lbs with behind the wheel. I plan on swapping it to manual steering which will shed another 30 lbs, so it'll be 3600 lbs with me and a full tank of fuel. That is almost 500 lbs lighter than my '70 Judge (4080 lbs with me)! I wish they put RAIV's in stripper Tempests in '69 and '70...they would have been game changers!"

The two cars are comparably equipped with V8's (400's), power steering, automatics (TH400's), radios, weighed on NHRA certified scales, with drivers. The Tempest was weighed without the spare & jack assembly (60 lbs.) and a half tank of gas (61 lbs.). If you add that to the Tempest's weight (with factory sound deadener, etc.) then minus the driver difference of 75 lbs. (3650 + 60 +61 -75 = 3696 lbs. with me (150 lbs.), or 3546 lbs. curb weight. The AMA curb weight of a '70 GTO is 3781 lbs. + 31 lbs.(PS) + 29 lbs.(TH400) + 8 lbs(radio) = 3849 lbs. curb weight. So that is a 400 lb. difference...sorry not 300 lb. My Judge weighs 4080 lbs. with me, or 3930 lbs. curb weight (exactly what my title lists) with the spare and full tank of gas, right on the AMA spec weights. The '70 Tempest is much lighter for some reason and weighs they same as my brothers '71 455HO T-37 (+/- a few lbs.).

The AMA weight for the '70 Tempest is 3336 lbs. + 245 lbs. (400 4-bbl.) + 29 lbs. (TH400) + 31 lbs. (PS) + 8 lbs. (radio) = 3649 lbs. curb weight vs. 3546 lbs. actual. AMA GTO weight of 3930 lbs. minus AMA Tempest weight 3649 lbs. = 281 lbs., so close to 300 lbs. by AMA standards.

Both cars are factory stock with all their born-with stuff...no weight removal in either.

Dennis

[Rocky Rotella]

Originally Posted by SD455DJ

Rocky, I think the 330 (345) hp rating was to keep the non-GTO power above the weight ratio to 10 lbs/hp max for insurance and NHRA class advantages. The 70 GTO was never lighter than 3700 lbs stripped, so even with the RAIV's 370 hp, it was no less than the 10 lbs/hp PMD seemed to ascribe to in those days. A stripper Tempest 2-dr post coupe could weigh almost 300 lbs less than the GTO, so 345 became the WT hp number based on the 10 lb rule.

Dennis

Thanks, Dennis. And I should have clarified, I'm not contesting the 330 hp rating, just wondering if/where the 345 hp rating is published in a Pontiac-printed source.

[muscle_collector]

as far as weight differences, 40 years ago john sawruck and I were talking about my 70.5 GT37 400 3 speed manual car and how much lighter it was than a comparable gto. we started making a list of stuff we could come up with. example, gto front bumper heavier than the gt, rubber mat lighter than carpet, really cheapo door panels, seats etc compared to the gto. he also sent me copies of paperwork from Pontiac that showed performance tests on all their 70 year models. and the fastest 1/4 mile time was a GT-37 400 4 speed (WT with 12 heads) and a 3:90 posi. yes it was faster than a ra4 gto and firebird.

[unruhjonny]

I would be interested in knowing which brochures ect have different ratings;
I had always assumed that the 350hp rating was used on the GP & A-bodies;
I thought the 330hp rating was only for the Firebird...

But, I just looked, and found THIS and THIS and THIS (there's also more in that prestige brochure) and low, and behold, there we have a 330hp rating on the Tempest/Lemans!

[UPC-WU2]

The ‘70 Powertrain Chart also shows 330hp.

http://www.gt-37.org/gallery/index.p...5&mobile=false

[Held for Ransom]

Here is the AMA doc.

[Diego]

For what it's worth, Sawruk also claimed the Tempest's 400 was the equivalent to the RAIII without the induction plumbing. We now know that not to be true.

[70Steve]

Hi Guys,
I recently saw an original type magazine ad for 1970 LeMans that I’d never seen before. I noted it stated that “Up to 345hp 400 available to order”...I instantly thought that was odd. I’d always thought it was 330hp for LeMans. Anyhow, I’d love to know where this ad appeared, seeing as it’s a 4 door Sport featured.

[70Steve]

Here it is ... 👍🏻👍🏻

['ol Pinion head]

Most likely the print ad was put together very early, before actual production. The 1970 mid size model brochure printed Sept '69 showed the avail of the 330 horse auto 400 engine, not the 400 WT engine. the 400 WT engine def became avail at some time, where we normally have seen it ordered was in the late season '70 1/2 GT-37. Occasionally, when analyzing the Prestige full line brochures as well as other smaller Pontiac advertising brochures, one will find details that aren't correct.

Earlier discussion & a few calculations; from what Mike Noun revealed as what one could call a Pontiac imposed 10.5 lbs per adv HP restriction on it's 1970 builds:

- the lightest '70 LeMans Sport w 10.5 lb restriction & engine rated at 345 HP would have to weigh 3622 lbs or more.

- by rating a 400 4bbl engine @ 330 HP, a '70 LeMans Sport could weigh as little as 3465 lbs & get by this "restriction". The 330hp rating of the small valve slightly lower compression 400-4bbl auto engine made sense compared to the factory rating of the other '70 400 4bbl engines.

- in actual builds, a '70 LeMans Sport built on the lightest body, the Coupe, ordered out w zero other options, but optioned with 400 4bbl, Muncie, & dual exhaust, is going to be close to 3650 lbs. a Turbo 400 equip 400 engine will weigh 29lbs more.

- with a 345 HP rated 400 being able to be built in the heavier LeMans Sport & make the arbitrary 10.5 lb restriction, knock off 71lbs to get to the AMA listed weight of a '70 Tempest Coupe with the same optional powertrain &, Voila, 345 HP is too high. So the politics of the 10.5 lbs per HP gets involved & any reference of an optional 400 4bbl engine in a '70 233-235-237 series shows the 330 rating, even if a 350hp 400 WT made it into the car.