Ive been doing some research on vortec heads on the l98 but i still have a few questions on it. So far im pretty sure they are a direct fit on the engine, but i will have to buy the intake manifold that fits the vortec heads. I plan on just doing the Head swap, and getting headers later. I also heard that the tpi intake manifold that fits the vortec heads flow very poorly, worse than stock.

Im wondering if i can pass smog with these heads, like will the egr valve fit the new intake manifold? What are the gains to expect from a swap to vortec heads and the intake manifold? with headers and with stock manifolds?

also i was reading up on the two different vortec head casting numbers, the 906 and the 602's. i guess the 602's are better?
Thanks guys, all help and info is greatly appreciated!

 

I see that you are in California. This is probibly not a good swap for you considdering how strict they are about emissions. The lack of a functioning EGR would likely cause you to fail for NOX.

 

bump.

 

Doesnt anybody know about the Egr valve on this?

 

Are you talking about the Scoggin-Dickey one? Is there a good Vortec TPI base out there?

Are there any others that do have EGR provisions on them?

 

What part of California are you in?

Yes you can use the Scoggin Dickey Vortec TPI manifold if you also use their EGR setup. But I'm not sure if they still sell it. Its similar to the TPI Corvette EGR with a tube going from the #8 primary to a port on the back passenger side of the intake manifold. Then there are internal passages in the intake manifold that direct the exhaust gas to the EGR valve in the standard location (top center).

Vortec heads require headers, as the stock f-body manifolds will not bolt up. That means you will need to drill a hole in the #8 primary and weld a connector for the EGR pipe.

In short, due to how terrible the Vortec TPI manifold is, and the hassles to make it work, you're better off spending the money on a regular Edelbrock TPI manifold, and get some Trick Flow aluminum heads.

 

Out of the box, the 062 heads are better than the 906 heads. I beleive (not totally sure) but I beleive the 906 heads have hardened valve seats which can interefere with flow. ...since you'll have to have some work done to accomodate even an "average" sized cam lift, the machinist can take care of that for you and then it really doesn't matter which casting you get.

I would agree though, once you pay for a little machining, AND the cost of the intake, which doesn't flow all the well anyway, they really aren't that great of a swap. GREAT swap for "other" manifolds, but not so much if you're gonna use a TPI.