'69 435HP Intake Manifold questions

[Kent K.]

Finally, we brought my old girl home from 3 years safe keeping. It presently has an aluminum intake manifold #3933163 from the Winters Foundry and a Holley carb 4781 with 2/2 below, front bowl 7047 4781 and rear bowl 7049 4781. First questions are what, if any, were the applications for these items?

I have the factory installed intake manifold and 3 dueces per the original owner who removed and stored them to install a 4 BBL carb/manifold for racing. The manifold is number 3937797 which, according to the TIM & JG, is for the 400HP car yet it came on this 435HP car. All 3 barbs are dated and numbered correctly for original. Is it possible for SN 726231 to have a 400HP intake originally installed instead of the 435HP intake?

Any help would be appreciated. I'll probably have many other inquiries.

Kent #6201

[Clem Z.]

Re: '69 435HP Intake Manifold questions

3933163 LS-6 intake and sold over the counter. 4781 universal 850 double pumper

[Clem Z.]

PS

i do not think the 400 HP manifold,oval ports, will cover the rectanglar intake ports on a 435 HP heads.

[Joe L.]

Re: '69 435HP Intake Manifold questions

Kent-----

The GM #3933163 was used on many 68-69 SHP big block applications, but none of these included any Corvette. It was available for years as an over-the-counter SERVICE manifold.

The GM CASTING #3937797 is the rectangular port manifold originally used for 1968 and early 1969 L-71.

[Clem Z.]

does that mean the TIM&JG is in correct ??? *NM*

[Joe L.]

Re: does that mean the TIM&JG is in correct ???

clem-----

It is incorrect if that's what it says. However, my copy of the latest edition available of the 68-69 manual does have it listed correctly as the L-71 manifold. One correction to my earlier post, though, is that it was used for later 1968 and all 1969 L-71. I "reversed" it. All these numbers and dates are hard to keep straight in my 'noggin.

[Mark #28455]

163 intake will not fit under BB hood

the 163 intake will not fit under the stock BB hood. Does your car currently have the L88 hood? If so, the air chamber will likely hit the 3x2 setup when you install it.
Mark

[Kent K.]

Correction and Thanks

Clem, Joe & Mark ----
Clem - the TIM & JG is correct, I simply read it wrong. Joe, your noggin is great; thanks for all the research you provide to this board and beyond. Mark, the hood was converted to appear similar to an L-88 hood. I might post a picture later of the aftermarket modification from the engine compartment side. BTW - Dicky (Papa Smurf) located a factory '68-69 BB hood and delivered it on his way to Kissimmee. Seems like we're set for breathing and covering the monster.
Thanks again. Kent #6201

[Kent K.]

Modified '69 hood

Mark --- This photo is of the hood as modified for the original owner for the 3933163 manifold and 4781 carburetor. The outer skin appears like the L-88 although my knowledge is slim pickings for those cars.
Kent #6201

[Mark #28455]

is it press molded? *NM*

[Kent K.]

Re: is it press molded?

Sure looks that way. What are your thoughts?
Photo of engine as I purchased car except for removal of triangular Elderbrock Ram-Flow air cleaner. None of the reproduction valve covers I've seen have the same configuration with brackets and lack of power steering indentation as these. All bolts observed to date appear to have correct head markings.
Kent #6201

[Mark #28455]

Valve covers probably original *NM*

[Kent K.]

Mark - you have email *NM*

[Howell Jaynes]

Re: '69 435HP Intake Manifold questions

Going back to the original question. If the car really was a 435 hp car, the 3X2 intake manifold would have rectangular ports to match the rectangular ports on the cylinder heads. If it was a 400 hp car, it would have oval ports to match the oval port cylinder heads. It seems hard to believe that the factory would put an oval port intake manifold on rectangular port heads. Also, didn't the 435 hp engines have aluminum heads?

Aside from part numbers, you can distinguish an oval port 3X2 intake manifold from a rectangular port 3X2 manifold just by looking at them even though they are installed on an engine. The rectangular port intake runners are noticeably larger.

[Kent K.]

Re: '69 435HP Intake Manifold questions

Howell --- Please refer to my posted correction above. I simply read the TIM & JG incorrectly. This car has the original L71 435HP engine including its manifold and 3 carbs that were placed in secure storage in 1981. They were replaced with the 3933163 manifold and 4781 carb by the original owner for amature racing and autocrossing. As to the heads, L71 435HP engines had cast iron heads. L88 430HP and L89 435HP engines had aluminum heads in 1968 and '69 per the TIM & JG, 3rd edition.
Kent #6201