Tweet
Does any one know if any 1971 Corvettes were built with the high rise 163 or 474 intakes? I know about the hood clearance issues but I wonder if any were ever built even at an experimental level. Thank you Bruce
-
-
Re: 474 or 163 intake on 71 Corvettes???
If you nean Built at St Louis and sold to the public, the answer is no.Bill Clupper #618 -
Re: 474 or 163 intake on 71 Corvettes???
Bill,I know about the factory numbers. I thought maybe a few factory autorized outfits may have built a few. Thanks.Comment
-
Re: 474 or 163 intake on 71 Corvettes???
Bruce-----
As far as an "experimental" or "prototype" car, who knows? This would have been a "one off" type of thing built at Warren. As far as a PRODUCTION unit, as Bill says, I don't think there's any way it happened.
For one thing, the neither of the manifolds you mentioned will fit under a standard 68-72 big block hood. For either of them to be used, the L-88/ZL-1 hood (or some other hand-built, "one-off" hood) would have to also have been used.In Appreciation of John HinckleyComment
-
Re: 474 or 163 intake on 71 Corvettes???
In additiion, for a St Louis Build car, The engine would have to be in "Certified" configuration, an expensive and time-consuming process that was not undertaken lightly by GM. If you think you have a car that ran thru one of the dealerships or independent shops who were selling Modified cars in the early 70's (Motion and the like) the federal regs were different then for "low volume" producers, but I don't know if the car could leaglly be sold as a "Corvette by Chevrolet" in the modified configuration or if it was sold as a MotionXXXXX. This is different than what Yenko and others were doing in the '60s, because they were using complete engines that had been certified for use in Chevrolet cars of that model year. Two issues arise between then and the 70's one, the cert process became carline specific, and two, I don't think any of the 71 pass car engines used the manifolds you referenced in '71, but I have not researched that. The Fedreal emissions regs were changing regularly in the early '70s and an intake manifold difference would certainly have triggered a certification requirement.Bill Clupper #618Comment
-
Re: 474 or 163 intake on 71 Corvettes???
Thank you Bill and Joe. I am building a 1971 Corvette for racing purposes. We don't have the the critical restraints of original cars or restoration projects. I have closed the 454 hood on the 163 intake, with no air cleaner or underhood insulation, and frankly it was tight but it did close. Our sanctioning body requires that a certain combination be an original factory car or something along the lines of Yenko or another authorized outfit like Motion. I'll run the car with the 569 intake and make the best of it. Thanks again for all of your help.Comment
-
The 163 intake is very similar to the 198
used on the 1968-69 L88's. The only way to make it work well is to use the L88 hood for air cleaner clearance. Without that, I bet the carb would be right up against the underside of the hood. The air cleaner base (factory curved style) was essential in getting the air to turn the corner into the carb and is likely worth about 15HP at peak power. Bill Jenkins (pro stock fame) even used to take stock air cleaner bases and cut them down to fit on his motors to help with the air flow.
If you had a choice of the stock BB hood with low rise intake vs. L88 hood and high rise, I would opt for the L88 setup.
MarkComment
Comment