At least on paper, I think the Z11 was 430 horsepower.

 

correct, advertised hp 430. we all know that story 70 w-30 = 370 hp yea right.lol

 

Power to weight, my friends. After GM lifted the no more than 400 ci in the A-body car for 1970, the guideline then was 10 advertised horsepower per pound. And a well-equipped Olds A-body just happened to conveniently weigh around 3700 lbs. So- 370 hp in an A-body with a hotter engine than a Toronado rated at 400 hp would have had.

But a race-prepped 63 Impala would have weighed nowhere near 4300 lbs, so who knows where they got that conservative 430 hp for Z11. Probably hedging their bets against the competition, plus NHRA/IHRA class factors...

 

The RPO 409s put out 425hp in 1963. So the Z11 was definately a bit more : )

BTW, Charlie it was our pleasure to be of assistance.

 

So how would that explain the LS6 Chevelle?

Was the hp/lb edict rendered obsolete by 1970 as well?


I don't think the edict was around in 1963, but I could be wrong. I am assuming a lot of these strict rules started with the racing ban. I should know this but never really got these things straight.

 

1963 is when GM "technically" & "officially" pulled out of racing.

 

The same way Pontiac got around things with GTO in 1964. Some things just happened, and everyone knows Chevrolet got their way more than the other Divisions did. Otherwise you'd have seen the HemiOlds in production in 1970.

Oldsmobile unfortunately played by the rules more than some of the others did.

 

Well, the GTO got past the company brass because it was an option and harder to discern. After the GTO's success, they changed the rules to be 400ci. Buick's Nailhead was 401, but marketing literature suggests it's a 400 to keep it within the limit.

 

This one was raced as "Fine 409" in New York.

 

^^^ Very nice.
I had a 63 with three
on the tree and a 327.

 

I love the 63-68 Impalas, I had almost one of each in SBC configuration. Fun cars, Stephano that is an awesome 63.

 

I have never owned one but I love the 63 Super Sport. It is very doubtful (not impossible) that a 63 SS would have come from the factory with blackwall tires. They would have been WSW's. Now a 409 Biscayne would have been another story. I love that black with the red interior.

 

Thanks guys, it's really an amazing package when you think about what GM was offering in 1963. This was the baddest Chevrolet other than the Z11 or Corvette Fuellie, you could get.

This one has a factory 4.56 posi.

The OE tires would have been 8.00 x14 with a one inch white wall stripe.