Originally Posted by 68/70Vette

I don't agree with some of the things I've read here about 454's.

The factory 454's were not internally balanced, the 427's were. If you have a 454 built up, you can have it internally balanced. Now it will rev like a 427. I would hope most built 454's are.

Breathing. Buy big block heads with rectangular intake ports. One rectangular intake port will have a cross sectional area that's equivalent to the entire exhaust of a Honda or Toyota economy car. GM says don't use the rectangular ports on a street car because the intake ports are too big...never had any trouble running rectangular ports on the street.

Sadly comparing apples to oranges doesn't help me,
Some Hondas and Toyotas with that little exhaust can and do spank hot c3's that's all they need so you see what I mean, but talking rectangle vs oval while I have not heard rectangle is too "big" for the street but rather for higher rpm, it seems they are reserved even by some bigger names in engine building for engines far more "race" that street, I fully believe yours works great on the street many factory cars came with rectangle ports but just like some cams are for low torque and some for high rpm hp oval ports are for one area and rectangle ports for another...
I do not know your driving style but if you are not doing higher rpms you don't "need" the rectangle ports and in some ways all other thing the same they might be hurting you.

Pig..The 454 shouldn't weight anymore than a 427. For Corvettes, the 1970 454's came out with cast iron manifolds...Arggh! The 69 427's came with aluminum manifolds. You can buy Edelbrock aluminum manifolds for your 454. or a 69 aluminum manifold will fit.

Pig Revisted...If you're building a big block for you Corvette, please buy aluminum heads. It really reduces the gross big block weight. Your Corvette will drive and handle so much noticeably nicer. A big block with aluminum heads and aluminum manifold weighs about the same as the all cast iron small block engine. Edelbrock makes aluminum water pumps for big blocks also.

I believe that aluminum heads on the bb make it weight the same as a iron sb but in my 69 when I went from a sb 383 to a 454 with iron heads I liked the "feel" of the handling better, now when my car comes back it will have a completely different suspension, the vb transverse front and rear, hopefully I can tune all that in to not loose any "ride" ...I am not auto crossing so I do not care about better handling.

Poor performing 454 truck engines. They came with the "peanut" cast iron heads. The intake ports were grossly restricted. The intake ports had a u-shaped cross section that some people likened to peanuts.
[COLOR="Purple"] They didn't "perform" poorly they were not performance engines they were truck engines...COLOR]

Building a 454 is yesterday's newspaper. Bore the cylinders out to get 496 cubic inches. Depending upon the block you may be able to go to 502 cubic inches.
No replacement for displacement is alive and well

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Factoid: The rectangular port aluminum manifolds for a 67 breath a little better than the rectangular port aluminum manifolds for a 68/69, since the 67 hood allows the carb to set a little higher above the engine.

Originally Posted by BBCorv70

Wonder how many people put truck 454's into Corvettes? Could be where the reputation came from?