Thread: Upgrade to vortec???

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My friend has a '95 GMC 1/4ton... 350 Vortec engine... It hauls really nice... Actually it beats my Trans Am, barly but still...
I was wondering if Vortec heads would bolt onto a Pre '85 enging... (my 350 is a universal 1975 crate motor from GM.)
And I know Vortec heads require a different intake manifold. I was also wondering if they make Vortec manifolds for Carbs since I have an Electronic Quadrajunk... (I want to keep all the electronics and emmissions right now cause I gotta take it in here shortly so I need that on there to pass.)

A Vortec heads will bolt on to all Gen I small blocks, including yours. There are a ton of carbureted intake manifolds available to you. Your compression ratio will be high because the Vortecs have smaller combustion chambers, you'll likely have to run premium gas. You should throw in a cam with some more duration while you've got the old heads off. Using a very conservative cam and intake with a stock Qjet carb, Vortec heads made about 50 more horesepower in my truck. I used some dished pistons to keep the compression ratio down which lets me run on 87 or 89 depending on how I set my timing.

You won't be emissions legal because no Vortec manifolds are emissions legal. The Vortec heads do not have the exhaust crossover passage under the carburetor which so there is no way to install them without modifying the emissions system which is illegal or something. I have my first smog coming up in June, I'm hoping to slip this thing through without noticing the aftermarket heads or intake (I painted everything Chevy orange so nothing stands out as aftermarket). If it doesn't pass, I'll probably do some fancy brazing and milling on a stock manifold to install just long enough to get me through.

Vortec heads do not have the exhaust crossover passage under the carburetor

Is that the splendid little valley where when you take the intake off you can see the push rods and lifters just above the cam???

The Edelbrock Performer Vortec manifold PN 2116 fits Vortec heads and a spread bore carb.

Originally Posted by weylinthedirty

Is that the splendid little valley where when you take the intake off you can see the push rods and lifters just above the cam???

Nope. It's a passage in the manifold that allows exhaust gas heat to pass through.

So basically I cant run EGR Valve on anything Vortec...

there is not any thing in the vtec head that you can drill out to get gas cross for EGR

Originally Posted by weylinthedirty

My friend has a '95 GMC 1/4ton... 350 Vortec engine... It hauls really nice... Actually it beats my Trans Am, barly but still...
I was wondering if Vortec heads would bolt onto a Pre '85 enging... (my 350 is a universal 1975 crate motor from GM.)
And I know Vortec heads require a different intake manifold. I was also wondering if they make Vortec manifolds for Carbs since I have an Electronic Quadrajunk... (I want to keep all the electronics and emmissions right now cause I gotta take it in here shortly so I need that on there to pass.)

Don't you live in Pinal County? If so, you don't have to emissions inspect.

I live in Pinal... But the only emmionstesting place is in maricopa where I live... I think????
And actually I was thinking about getting a PO Box in Pinal and using that when I do all that junk... My friend Jake does that and his tags are always good for 3 years lol.