When was the 4X head installed on the 400?
The codes are listed below. The 4X head was installed on the 400 and 455 during the mid 1970’s. Most I have found are 455 stamping. 3H 2.11/1.66 valves 98/101cc’s. These cc figures are approximates, as I have found most slightly higher.
Can a small block V8 handle a 4bbl?
A ’72 small block V8 should be able to handle a small 4bbl (like a 550 cfm), but, unless you replace the intake manifold with a 4-bbl manifold, a 2bbl-to-4bbl adapter will kill most of the advantage of adding a 4bbl. Plus, the factory-style single exhaust is pretty restrictive. If air cannot get out efficiently, It cannot get in efficiently.
How many horsepower does a Chevy 4 barrel engine have?
The engine displaced 260 cubic inches. The horsepower was 167 with the regular 2 barrel carburetor and 177 if the four barrel was ordered. I don’t know if the four barrel came with dual exhausts or not. Chevrolet offered a package of a four barrel carburetor and dual exhausts on its 265 cubic inch engine for 1955.
How many horsepower does a Chevy small block engine have?
On engines in the 280- to 350-hp range, it was common to pick up at least 10 hp, with 15 being about the norm—on one occasion I saw as much as 22 hp. I have to stress at this point that the porting done was only basic. It involved port matching to the manifold gasket (usually a Fel-Pro) at the top and sides, but the bottom mismatched header style.
Do you need a lower intake for vortec heads?
You might want to email Weiand on Holley’s site and inquire about buying a lower intake for those Vortec heads. Vortecs will work fine with high compression naturally-aspirated or a blower application.
When did the 4 barrel intake manifold come out?
Its coolant passages and mounting points were revised for 1965, making it compatible with popular Pontiac cylinder heads commonly used today. Pontiac introduced a new 4-barrel manifold when multiple carburetion went away for 1967.
The codes are listed below. The 4X head was installed on the 400 and 455 during the mid 1970’s. Most I have found are 455 stamping. 3H 2.11/1.66 valves 98/101cc’s. These cc figures are approximates, as I have found most slightly higher.
What kind of intake do I need for my 350?
Check out some Brodix IK’s – they’re much more durable and flow well, plus they’ll fit your current intake. June ’06 Car Craft has a story on a 445 HP 350 with Vortec heads and the Weiand 142 blower. You might want to email Weiand on Holley’s site and inquire about buying a lower intake for those Vortec heads.