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Discussion Starter · #1 ·
OK here's the deal- there was this discussion going on over in engine performance about adding vortec heads to a 350 engine. The gist of the thread was that this was a direct bolt on - no problemo- I couldn't get an answer there so I came back here where the wagons are cause lots of us have L03 or L05 engines. Has anyone done this? Do I need to swap out intakes or can I just bolt mine back on or does it need machining to fit? I'm afraid that if I go to the truck intake I'm going to have clearance issues since my caddy intake is already rubbing on the hood. Hopefully I'll get an answer here..

If you want to check out the thread, it here:
vortec on 305/350 thread
 
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Discussion Starter · #2 ·
The intake bolt pattern is different on the vortec heads. You have a few options, if you buy NEW Vortec heads, I believe it's Scoggin-Dickey sells them redrilled for the earlier intake bolt pattern. OR you need to dig up a '96+ truck intake.

Good luck! If my '92 didn't have a completely clapped out 305, I would probably go that route on mine too.

-Dave
 
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Discussion Starter · #3 ·
zooooooooooooooooooommmmmmmmmm............that was fast! I was just doing a search on it and my reply is already here! That's what I like about the wagon section- always there to help!!!

:D
 
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Discussion Starter · #5 ·
Roadmonster, if and when you do it, can you let me know the outcome? I started that thread from something I heard on the street, but you know how that can be. Once I get my money together, I'm on it... unless I hear otherwise.
 
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Discussion Starter · #6 ·
Well this is not a wagon. But I have a L03 On a Sierra that has No power! Im talken valve train probs, Ticks, Smokes at startup sometimes, Burns oil all at 108k.

It looks great. The engine does not perform.

The thing keeps runnning but gets owned on the highway so a 350 is in the future VERY soon!

2 places have 350s that I would consider. One for TBI engines (285 hp) and one for vortec engine ( 300hp) They both have baby cams in them right now and require 91 of higher octane.

Now Im kicken around, Go vortec or keep the TBI parts.

Im just wondering if a TBI intake will work on a vortec 350, Or I was thinking about a MPFI intake with a reg TB. But that is $$!

Also Edelbrock makes a few Intakes.

There are so many options!


If you use a 96+ Truck Intake, Will the TBI throttle body work on it? I think the whole vortec conversion would not be that difficult though.

I recall someone here installed a vortec 350 in his 91 wagon I think.
 
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Discussion Starter · #8 ·
A Vortec head swap on the wagon would be a wonderful addition to the L05. Vortec heads are basically LT1 heads sans the reverse cooling nonsense. Similarly, GM FastBurn heads are aluminum versions of the same thing.

Vortec's use eight vertical intake bolts as opposed to the non-vortec small block's 12 ****** ones. For that matter, pre-1986 small blocks used 12 bolts at a different ******-angle.

Other than that, everything else is the same. Like any small block, the intake & exhaust port locations are the same, coolant passages are the same, exhaust manifold bolt pattern is the same, yadda, yadda, yadda....

The vortec heads are intended for the self aligning rockers. I don't know if the L05 is...probably. Pushrod length *shouldn't* be a problem, but you shoudl probably check it.

So, quick breakdown. You need:
Heads
Intake (Aftermarket, '96+ truck, redrilled heads to accept normal intake...)
Gaskets
Proper intake bolts

That pretty much covers it.

-Dave
 
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Discussion Starter · #9 ·
Yeah. I just got that info of intake not ligning up at the Fullsize chevy forum.

GRR!

Would you think I would be possible to use the whole Vortec Manifold and the TB that is included with a Vortec engine?

Is the wiring that much off?

Well A vortec intake for a B-car would require the distributor hole would to be larger. Correct?
 
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Discussion Starter · #10 ·
As far as an intake goes why not using something like a Weiand Stealth, they come in Vortech versions and then use a 4bbl to TBI adapter plate, I know that adds another 1/4"-1/2" but maybe an after market intake is a bit shorter than the truck one. I have no proof of that it is just an idea.
Nick
 
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Discussion Starter · #11 ·
Yeah the hole has to be drilled larger. Also if you go with a truck intake and TBI you either have to modify the cruise control or get rid of it. My main concern is the height under the hood. My airbox scrathes the hood already any extra highth and the hood won't close.
 
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Discussion Starter · #12 ·
well i know that 87-95 truck intakes are about 4 3/8 tall measuring with straight edge on tbi mounting flange. measure from straight edge to floor front and rear of intake manifold.and divide a (front) & b (rear) by 2 just went out garage and measured.don't have intake for our cars 91-93.but this measurement is an average height.
 
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Discussion Starter · #14 ·
Also, I discovered by swapping to Performer RPM manifold this past week, the surface the distributor sits on is 1/8" lower on a B-car manifold than a standard Chevy manifold. The area below the distributor mounting surface, on the passenger side of the manifold must be removed to allow the distributor end to be angled into place. I'd be glad to share the rest of the fun if you want more details. ;)
 
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Discussion Starter · #15 ·
If you had a truck, You could use a vortec Carb manifold using a TBI adapter plate right?

What about the EGR though?
 
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Discussion Starter · #17 ·
Originally posted by PaulD:
Also, I discovered by swapping to Performer RPM manifold this past week, the surface the distributor sits on is 1/8" lower on a B-car manifold than a standard Chevy manifold. The area below the distributor mounting surface, on the passenger side of the manifold must be removed to allow the distributor end to be angled into place. I'd be glad to share the rest of the fun if you want more details. ;)
I would like to know more about this. Next spring is supposed to be Vortec time for me and I would hate to get half way in and have the distributor not fit...
Nick
 
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Discussion Starter · #18 ·
OK I'm ready to do this thing-

PaulD how about sending me the info if you have it on this swap. I don't want to do it blind. I figure L31 heads- Performer intake and 454 TBI with an LT1 cam- let's see what it does.
 
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Discussion Starter · #19 ·
That sounds very similar to my plan. Only difference being the TB itself. I have only one suggestion, when it is all done, spend the money to have a very qualified person tune the car on a dyno. I think the TBI cars get a bad rap as nonupgradable because people spend $1500 on parts and the car just lays over and dies. It seems to me they are dying due to lack of tuning. Just my .02, I cant wait to see how this turns out.
Nick
 
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Discussion Starter · #20 ·
I have a whole vortec engine in my wagon. Here is a list of problems with the swap. {1} the very rear exhaust manifold bolt on the right side won't bolt to the vortec heads. [2] You will have to ditch your egr valve. The vortec heads don't have the passage. They got exhaust gasses off a hole in the exhaust manifold. [3] I have an adapter plate on a vortec performer intake and the fuel lines didn't quite fit. I suggest forking over the $300 for the GM tbi vortec intake. I have 2 cars with vortec heads and I love them. On my race car they were worth 2 tenths of a second improvement in the quarter mile over the trick flow aluminum heads I was borrowing!
 
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