X-11 heads

[habanerored52]

Hello people
I was watching on youtube a video from Sehr Performance where they took a Chevy 229 ci. 3.8 L. 90 degree V6 and turned it into a 501 hp screamer. The video said they used X-11 heads. The only reference I could find were on a 1980 Chevy Citation with a 60 degree V6 engine. Will these fit on my 229 ci. 90 degree V6 ? If they will fit, what year and engine code ( LH7,L32,or LE2 ) would be the best to use ? I plan on using a hyd. roller cam and a 4 bbl. Holley on the build. Thanks.....

[pocket-rocket]

Since they are totally different engine families, I really doubt it, especially if you are using iron heads to try to hit that kind of power level without boost.

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[habanerored52]

weren't some of the X11 heads aluminum ?

[bszopi]

Nope.

Brad via Tapatalk

[geoffinbc]

The Chevy 90*V6 has a lot of aftermarket heads and factory performance options. Well at least it used to. So at some point there may be some heads called X-11 heads but they were not off of the 60 Degree V6 or out of a Citation. While the engines do share the same bore spacing they do no have a similar bolt pattern at all (the 60 Degree uses 4 bolts per cylinder while the 90 degree uses 5) and the heads are a completely different shape.

The best OEM heads for you would be 96+ Vortec heads or if you have the cash buy a set of aluminum heads from GM Performance or Brodix.

[SappySE107]

Which 90V6s uses 5 bolt? The S2 3800 heads I am doing now are close to the 60V6 pattern but not compatible.

[robertisaar]

the chevrolet 90V6(which eventually ended up as the 4.3) LOOKS to be more or less 5 bolts per cylinder.

[TurboGTU]

Probably the 4.3 carb heads. The 229 had tiny valves but prob flow more than TBI 4.3 heads on the intake side. Never seen carb 4.3 heads but I'm sure they don't have the restrictive swirl port of the TBI head.
I had a or still have a 229 and that thing is a odd ball. Semi odd fire crank makes cam and ignition choices low. She was a shaker too.
4.3 is a 3/4 350 SBC and a 229 is a 3/4 305 SBC. Hotrod did a 4.3 build but started with lousy TBI heads. No more 90* talk lol

[geoffinbc]

The Chevy Power Manual has a lot on the 4.3L. As far as I remember all heads up until the CPI motor came out were the same. They called the CPI heads "Vortec" but the "Vortec" heads that everyone refers to that had the good (for factory) flow numbers did not come out until 1996. But the CPI heads are the exact same intake bolt pattern and angle as the early heads so they are a cheap and easy upgrade. 96+ heads require a new intake.

[habanerored52]

Thanks everybody for their replys. TurboGTU....I put a crank from a 1985 4.3 into my 229 and made it into an even fire engine. The stroke is the same as the 229 and both are 2 piece rear main seals. The reason I used the 4.3 crank was because aftermarket forged rods and hyd. roller cams were easier to come by . i also had to change the distributor to an even fire. I didn't know the 4.3 heads would fit my 229. I know the Vortex wont fit because by block is a 1981 model. Sorry for the 90* talk .....