Close.

When Vince Piggins was "fooling around" building an SCCA T/A factory race car (soon to be known as RPO Z/28) he was using the high performance version of the 283 ci V8 because that's all Chevy had developed at the time that fit within the class restraints.

"The only thing. . ." continues Vince, "while we were driving the car (with Pete Estes), I mentioned that we'd put the 283 into it because we'd built that size engine before. But I suggested when we got back to the starting pad that it might be a lot better to take the 327 block and put the 283 crank into it, giving us a 4 x 3 bore and stroke. That would put displacement at 302.4 cid, just under the SCCA's 305 limit."

Therefore, technically the Z/28 in concept predates the creation of the 302 ci V8.

(Furthermore the 327 block was used and not the 350 because only the 327 shares the 4-inch bore. However, if you check GM block codes for 1967, the 302, 327 and 350 all shared the same casting.)

Piggins continues...
"So Pete immediately agreed, especially being an engineer and knowing the potential this car could have. Estes walked over to engineers Alex Mair and Don McPherson and said, `Let's release this package and develop a 302 engine to go with it.'

The actual Z28 work order was #19621-34 and read as follows:

* Remove engine and send to motor room

* Install engine #196231 - A high performance 283

* Engine weight was 572

* dated October 11, 1966

"That was really the start of the Z-28, and we proceeded to homologate that vehicle with the FIA as of Jan. 1, 1967 as a Group II car."

 

the vette you are describing is also a ZL1 car...i was rated at 430 just like the camaro, the tri power 427 was 435....this car on the bias ply tires was a low 12 car...on slicks it was trapping over 130mph...they have one of the two in existence in a book called "american muscle cars"...its white and black, the other is red...there was a third but it was destroyed

 

No. "Back in the day" they did gross horsepower, which was an engine on a dyno with no belts/accessories on it, and dyno induction and dyno headers. The numbers, for the most part, were quite "generous."
The exceptions to this rule were the ZL1 and L88 engines, both 427s making upwards of 550+hp, but rated at 430 by the factory.

 

I know this will sound off the wall and you all wont like it im sure, but I have a ford 302 from a 79 and Ive been interested for a while in making a 302 replica I mean same or close to specs as the D-Z28 I know ones ford and the other is a chevy, but could some one give me some specs and what do you mean when you say it wouldnt be streetable or very drivable?

Ive talked to people and they say the best you can get is 360 RWHP and have it streetable, I say if im worried that much about it I would build my lt1 up , this is my first engine build and i want to do it right!

Im looking for around 400RWHP and keeping it N/A Ive posted on Stangnet.com they cant help me so good so I hope someone here can, thanks!

 

You may want to look into getting a set of 351 4 barrel heads or the heads that Ford used on the Boss 302( the same ones AFAIK )

There's been 30 years of tech out there to get more h.p. out of your engine. Check with a Ford related group for better specs on a 302 Ford engine that can output the numbers you are looking for.

On a side note, when I worked in a machine shop I had a couple of co-workers that had to rebuild their 302's and 351's at least 2 times a year because they would continuously break them at those h.p. numbers. I can't say that they built them right but from the expense and time they put in it sure seemed like they were doing a correct rebuild.

...Ron