Since I pulled my 305 to discover it had rust in cylinder #2 and it had a bad vibration between 2800-3400, I am choosing to drop in a completely rebuilt 97 Vortec 350 I found for sale out here. Thought I would start a post to track progress. What I have to keep reiterating to myself is that this is my daily driver and not the racecar, that still needs to be finished this summer. Going with an EBL for the ECM, but I need to get an intake. First question would be which one, stock, edelbrock or GMPP. Second question, am I going to be kicking myself for not swapping the cam out prior to installing it. Again, this ain't the racecar and the more $ spent here will hurt progress on the Z-28.

Another question would be what wideband O2 sensor should I get?

Does the stock TBI mount to a vortec manifold?

Anybody got a good reference for motor mounts? I'm sure that mine are dried out.

I found motor mounts for thirdgens for only $9 from Summit. I heard people on here say that they were around $80. Anyone use these.

The stock TBI will not bolt to the vortec manifold, You will have to buy a TBI manifold made for vortec heads or buy a vortec style four barrel manifold and use an adapter for the tbi. The vortec cam is actually a decent cam for the TBI cars, you can run it on a stock tune.

With EBL u use the stock 02 sensor. The wideband would be complementary for WOT tuning.

For the least amount of headaches use some ported swirl ports and the vortec short block. I believe the stock intake and throttle body flow enough for that engine. You would need some 55lb. injectors with the fuel pressure turned up a bit. Find posts by Fast355. He's got some impressive results using ported swirl ports. Since it's a street car they've got the torque lower in the powerband where it should be. I've done the Vortec TBI swap and if I had to do it over again, I would use some worked over swirl ports. The swap would've gone much smoother plus the car is a street only daily driver. Just my opinion based on my experience with the swap. But if the engine is to good to pass up then use the Vortecs.

Gene

First, thank you all for the replies!

I was just wondering what would be a good WB for tuning. I looked around and don't know if I need a 3 or 5 wire. I see some have the ability to datalog themselves, but I would think that I would just want to log with the EBL software.

Gene,

I've read some things on people using the the LO3 head on 350s and getting some good results. I know somewhere that you should stay away from the swirl ports, but have read also on what Fast355 has done.

The long block is assembled right now. I guess I could sell the vortecs, use my current LO3 heads, have them ported, and keep the stock manifold and TBI set-up.

What should I be looking to spend on porting the LO3s?

I guess the other option would be to either pull a vortec manifold and TBI or use the carbed manifold and an adapter plate.

Anyone else have some input?

Thanks again,

Mike

Hell, if you already have the longblock all nice and freshed up, might as well leave it alone.

The vortecs are good heads. Especially, I wouldnt want to try running 305 heads on a 350, you would probably need hi-octain gas for that. I believe the vortec cam is similar to the stock LT1 cam, except more for torque.

No reason to tear into that perfectly good motor if you want a reliable DD. I would probably spend the extra money, and get the GMPP Vortec TBI manifold. I believe summit sells it too, and so does gmpartsdirect. It will bolt right up to your heads, and your TBI will bolt up to that. Its like $350 though, but its a real GM part too. And I believe it uses that Vortec style EGR valve.

Slow,

I am thinking the same. I really don't want to tear into a perfectly good motor. Does anybody know the difference between the Edelbrock and the GMPP manifolds other than the $100 difference.

I read about how the EGR is tapped of the exhaust on the vortecs, which sucks cause I just got some coated 2055 hookers.

So will the LO3 TBI bolt to it or not? I'll have to search on that one today.

Thanks again, everyone.

GMPP will bolt on vortech's and your TBI will bolt on it.

EGR, you can plumb it up from the y pipe.

One thing I had to do with the GMPP Vortec TBI manifold was bend the fuel lines because the throttle body sits higher using this manifold as opposed to the stock manifold. I also had to custom bend another brake vaccuum line because the vaccuum port is in a different location as opposed to the stocker. And the port for the EGR valve is in front as opposed to the rear on the stock manifold. A few issues that need to be dealt with but nothing major. If you want to see some pics of it I believe I posted a few in my 383 TBI Camaro thread. There should be some there.

Gene

Graebz28, the edelbrock (is it like 3704 or something) TBI manifold is made to bolt to old style GEN1 heads like the swirlportr or TPI heads, or carb heads, or whatever.

When GM designed the vortec motors, they raised the intake ports quite a bit. Therefore, even if you drilled out a non-vortec intake to fit, the ports would not line up where the intake meets the heads.

The GMPP intake, is like an "adaptor" of sorts, which your old fashioned TBI will mount to. However, it also has the raised intake ports and relocated bolt holes so that it will bolt on to vortec heads.

Slow,

Summit shows a Edelbrock for vortec heads, but I think that it is for a carb. I could use an adapter plate, but then would lose the EGR.

Unless I find a used GMPP, I think the best/cheapest option would be to go to a boneyard and grab a stock manifold, with the EGR, ECS and knock sensor. Probaly not going to get that much gain from just the GMPP manifold, plus 350 is alot for an intake. I still need to get the EBL, WB, etc. If I get board with it, I could just add the bottle.

When using the vortec cylinder heads with TBI your only two options for manifolds are the GMPP Vortec TBI intake or a carb intake for vortec heads.

Gene

Yeah, there is no factory TBI manifold, that will bolt up to vortec heads.

Are all vortecs MPFI?

MPFI has nothing to do with it. None of them came TBI, so therefore you are trying to make a motor combining TBI with Vortec heads, something not many people in the aftermarket world consider worthwhile. The only manifold that is there for this is the GMPP one.

The biggest user of vortec heads, is people who do budget carb builds. Thats why there are so many carb-vortec intakes. Vortec motors never came carburated either.

I believe that TBI was made illegal in the 90's for vehicles below a certain weight (i.e. huge like contractor trucks can still use it) right around when GM started putting vortec motors in their trucks and S-10s.

You are WRONG there. GM manufactured TBI Vortec intakes both for Export trucks and Marine engines.

Illegal ? Hardly.

If they were illegal, there would be a law. And if there were a law, there would have to be some fact-basis for the law, and the lawyers and politicians would have to sit down, understand the technical issues and then spend time drafting the law. Then it would have to get passed by the house & senate. That's a lot of sequence IFs that need to be satisfied.

TBI was Darwin'ed out because the fuel delivery, in theory, is better controlled with MPFI. The extra cost of MPFI was in turn worth the gains in emissions control, cylinder-to-cylinder efficiency, and possibly a small improvement in mpg. That's why TBI was phased out in favor of MPFI.

Carburators aren't used on new production vehicles for many of these same reasons.

The only illegality is if you took , for example, an LS1 Vette and removed the MPFI and replaced it with either a carb or TBI. That would be in illegal act because neither the carb nor the TBI were original equipment in so far as emissions certification. No one would bother to emissions-certify a carb, either from a mfg or by a private (and rich) owner because it would make zero sense. But that doesn't make the carb or TBI illegal. It's only illegal in a retofit sense, because it violates emissions (EPA) laws. OTOH adding a TBI to an older car/truck is perfectly legal because the emissions laws associated with an older vehicle were minimal --- and TBI would certainly be an improvement.

Bottom line I guess is that I am not going to find a TBI vortec manifold in the boneyards. I thought since GM made a vortec TBI that it was a factory replacement, not to retrofit a TBI from an older motor. That's cool they actually did that, since I would expect the aftermarket manf to be the ones to see and fill that need. But, it was made probably due to the fact Fast brought up.

OK then, I'll either save for a GMPP or get an aftermarket carb'd one and the adapter plate. I don't have to worry abut emmission here in MO, but I have to pass a safety inspection and they may or may not be keen about the EGR.

Do you guys think I would benefit an ExtremEFI 46mm TBI or just do the ultimate tbi to my 305 and replace the injectors w/ 65lb/hr ones?

I already have an adjustable FPR, is a vacuum adj one going to save me trouble down the line with the EBL?

What about a pair of summit roller rockers?

You don't need a 46mm TBI --- the stock one will flow enough air to support over 330+ fwhp. The ultimate TBI mods will help if you modify the engine into the 300+ hp range. Yes, use the 65 #/hr injectors and I don't think you'll need the vFPR.

Why not the 55# with 35psi? Should be good for 330hp.

I have a similar pump to the walbro 190. I DO NOT want to change the pump. What would the best option be. I'd rather not have to buy anything else.

Sounds to me like you need to get an intake with adapter for the tb. Use the injectors mentioned and if you are going with the EBL get it.

The cam and rockers are up to you and how much you expect to get out of the engine. I don't remember the specs on the cam you have. After reading your sig you have what sounds like a fast 83 Z28 for a real speed fix so I'd keep this swap on the cheap and put that cash into something else.


DM

Thanks DM. That is what I need to keep hearing .... keep it simple and cheap so the real money can go to the Z.

Now to open a new can of worms! What about the Edelbrock MPI kit to use the 87-95 TBI with a Vortec. Only see old posts on this one.

To go with the GMPP manifold:

Manifold 360.
Injectors 150
EBL 390
WB 200

= 1100.

I can get the MPI kit for 1000, and have them burn a custom chip free of charge. Draw back would be that I would really like to have the EBL since I am a control systems engineer and have been dreaming about tuning my own car. I'm sure by now Edelbrock has got their tuning skills up to par.

I could go with the edelbrock tune for the time being, with the ability to go to batch fire EBL down the road.

The Edelbrock tune flat sucks for any of their setups. Not to mention the tune is for a truck and trucks have a seriously different tune than a car.

The way I see it, run the stock 305 55# injectors, just use the regulator for a 1994-1995 high pressure TBI setup, really only a stiffer spring. Upgrade the pump to a TPI pump, as you already need to up the pump anyway. I would suggest the Flash EBL, and forgo the need for a chip burner or chips all togather. Wideband is not a necessity, I tuned for a long time without one.

Thanks Fast. I going nuts again with visions of seq port, cams, rockers.....

So, I just won a bid on a Vortec GMPP manifold from ebay. It is bored out to 2" in case I mod it later.

Can I run 55#/hr inj with a 190 pump? If I have the choice to change pumps or injectors, you know I would go with not changing the pump. I do have an AFPR already.

Found a good post on Vortec motors and cams on another board.

http://www.fullsizechevy.com/forums/.../t-226749.html

I copied some good info below.

1996 LT4 Corvette cam with
203°/210° 0.050" lift and .446/.450" lift with 1.5:1 rockers or 0.476"/0.480" lift with 1.6's on a 115° LSA.
p/n 12551142

Stock L31 Vortec 350
192°/197° 0.413/.427" on a 111°

As you can see the LT4 cam will work within the stock Vortec 350 heads lift confines of 0.475". It will give you good all around power and decent fuel economy.

there is also the Ramjet 350 and HT383 crate engine camshaft
196°/206° .431/.451" lift with 1.5:1 rockers on a 109° LSA
p/n 14097395


L35 Vortec 262 4.3 V6 96+ fullsize trucks 200 hp
L30 Vortec 305 5.0 GEN-1E V8 96-99 truck up to 2002 vans 225-230 hp
L31 Vortec 350 5.7 GEN-1E V8 96-99 truck up to 2002 vans 250-255 hp
L29 Vortec 7.4 454 GEN-1E V8 96-2000 truck 290 hp

LT1 5.7 350 GEN 2 V8 92-96 Vette 275-305 hp
LT4 5.7 350 GEN 2 V8 1996 Grand Sport and Collector edition and LT4 Vette(6 speed only), only 33 1997 LT4 Firehawks, only 99 LT4 SS Camaros rated at 330 hp but actually 300 rwhp or about 370 crank hp
L99 4.3 262 GEN 2 V8 1994 Caprice 200 hp
LT5 5.7 350 90-95 ZR1 Vette(manual trans only) DOHC 32 Valve 385-405 hp

Anything has to be better than the L31 cam and its running out of breath above 4500 rpm.



What do you guys think about the last comment about the cam?

Thats all you need. With EBL you get an Excel calculator that will tell you how much psi you neet to set the AFPR for approximat hp.

This is exactly what I have. I used 1.6 rockers and DID NOT have enough clearance. You need to check clearance for yourself. You also will find that different folks state different numbers.

What I did was use Crane offset locks and spring shims to gain IIRC around .050.

Well, I only want to do this once, and am OK with holding off on the Z-28 for one more year. So I picked up the TBI GMPP intake, and a GMPP LT-4 hotcam, rockers and springs are on the way

The valve springs say they will work on any GEN I. Has anyone used this valve train on a Vortec 350?

From reading Fast's stickey, I need to get a timing chain cover and a timing chain as well. Summit has some that list they will fit any GEN I block. i have not pulled of the cover yet, but I can see that it does not use as many bolts as the LO3 does. Any suggestions here.

I sent out my ECM get EBL'd last week. Thanks Uncle GW for the rebate check

What springs are those? Did you get the hotcam kit?

Yep, bought the complete kit on ebay. From what I read online last night, these are the same springs as the old Z-28s with LT-4 retainers. Looks like I would need to have head work done unless I go with comp cams beehive springs. I think someone else on the board ran some crane springs that will work as well.

Maybe I'll just put on the 1.6 rockers since that will bring my lift up to .450 and leave the cam for later since I think I would need a new timing chain, springs and retainers.

Anyone see the springs on ebay for vortec heads?
http://promo.ebay.com/ebaymotors/ws/...&storeid=53416 1&downgradeDomain=true

He claims .550 lift on stock vortecs.

You're going to need guide clearance work to run the hot cam in any form with stock Vortec's. [IE: 1.5 or 1.6 rockers.]

I thought that the hot cam kit came with the LT4 springs?

From what I read, the LT-4 springs are similar if not the same as the Z28 springs.

This article below states that the comp cam valve springs do not require any machine work for up to .550 lift.

http://www.carcraft.com/techarticles...ade/index.html

Ya know back in the nineties before I had the internet and read what I could I was steered wrong more than one time. If you read that article they keep saying no machine work for more lift with those more expensive springs. Well that may be true for spring fit but you still have as I said earlier the guides will still have to be machined for that high of lift.

You can use offset valve spring retainers and shims, they will give you .050" more clearance between the retainers and the valve guides & seals. This will let you run .525" lift rather than .475".

So they say.......I only had around.460 and so after doing as you said it was at .510 which does not give the suggested .050 safety clearance. But I have been running a .480 lift cam that way for 7 years.

The last 3 sets that I worked with, gave .450" lift with a .050" safety clearance. The offset shims bumped it up to .500" lift. I rarely run more than .030" safety clearance and have gotten away with it on several engines that have turned 6+K with no issue. Is it the smartest way, possibly not, but it has worked for me.

I totally agree DM. I appreciate your comments. At this point, I am sort of regretting this approach. The cam purchase was an impulse buy. I considered for a moment to ditch all the vortec stuff and get some regular heads to bolt on the vortec block.

Now that I have to pull the heads, what is the best option? Just keep the LT-4 springs and have the heads worked to use them? Anyone got a cost estimate for that?

Then it sound's like I actually got more than you when I ended up with .510. Which is what you run.... .030
----------
My two cents would be what cam do you really want to run? If you can get your cash out of the cam and springs just use the 1.6 roller rockers with a cam that has lower lift. But since your have all the parts reworking the heads might be the cheaper alternative. But also the larger cam might be worse on gas than a lesser one. I say this because IIRC you said this is a DD. But my tuning skills are still not developed enough yet even with a 305 to get what I call good mpg. 18 to 20 mpg mixed on good weeks.

Just don't try a kimura on me if you don't like how it works out........lol

OK, got a garage full of parts. GMPP manifold, hot cam, rockers, and EBL on the way.

As far as the heads go, since I am using 1.6s, from what I have read I need to elongate the push rod hole. Comp Cams makes a guide for this, so I'll buy that and do it myself.

From everything else that I have researched, I am going to go with the beehive springs. I am always for a better designed part, and these clearly appear to be a significant design improvement and almost half the weight. (LT-4 Spring are for sale!) And, I should not have to alter the valve guides. Should I order shims just in case?

Now another concern ..... rocker studs? Can I get by with pressed in studs for a year or two or should I put in studs? I looked into pinning them and think that if I need to do that, I might as well do it right and get them studded. If necessary, what are studs that can be used w/o machining down the stud boss? I'll go buy a drill press and tap them myself if I do not have to cut the bosses.

Timing chain? There appears to be a new one installed on my motor. I know that the cam gear is stamped GM. I do not feel like spending 250 on GMs hi-performance set.

I'm thinking to just reuse my timing chain cover off the 305. That should work since it is a 1990 block, right? Any other suggestions here. A two piece would be nice, but see no need unless someone recommends an adjustable timing gear.

Anything else to check while I got the pan off?


A Jedi only uses Jiu-Jitsu for defense, never for attack.

[As far as the heads go, since I am using 1.6s, from what I have read I need to elongate the push rod hole. Comp Cams makes a guide for this, so I'll buy that and do it myself.]

Don't waste you cash...I did it 8 years ago with a carbide burr and a cordless drill......................



[From everything else that I have researched, I am going to go with the beehive springs. I am always for a better designed part, and these clearly appear to be a significant design improvement and almost half the weight. (LT-4 Spring are for sale!) And, I should not have to alter the valve guides. Should I order shims just in case?]

LT4 hotcam lift is with 1.6 lifters .525 IIRC.....You will have to machine the guides........sux as it may I know.....I feel your pain young Jedi........



[Now another concern ..... rocker studs?]

No way that I would suggest .525 lift without fastened studs.....



[Timing chain? There appears to be a new one installed on my motor. I know that the cam gear is stamped GM. I do not feel like spending 250 on GMs hi-performance set.]

Chain sounds fine........not building a Nascar engine....



[Anything else to check while I got the pan off?]

I know it sux but you have to think when doing this..lol........go through each step because the little details will bite you in the axx unless you are not in a hurry.......

Should I just get a smaller cam?
Should I just run the stock cam with the 1.6s?
Should I run the hot cam with stock rockers?
Should I put the hotcam in my 406 and run that this summer? Shoot, that won't work, it's a non OEM roller

I am really having buyers remorse. I'm taking the day off tomorrow and calling some machine shops to see what costs will be.

I talked to the comp cam guys, and they confirmed that the valve guides need to be machined. They sell the tools, but I would imagine that you need a lathe to do this work.

I wished I had a buck for every time I felt that way........lol

What lift is the stock cam?

I have a new set of the cutters and seals that I decided not to use. You can use them in a drill or drill press. The machinist that I seen do it used a hand drill. Don't know if that's correct or not but you are just cutting for seals.

FYI it would be a milling machine not a lathe.

Thanks again for all the help DM. Seems like this has turned into a 2 person thread!

Why not just go with e-techs at this point

The comp cam guys gave me part numbers for the tools and arbor:

4726 Cuts valve guide to .530
4733 Cuts valve seat
4732 Arbor

503-16 Seals.

If that is what you got or equivalent, then I could use them. I may go get a cheap drill press and do all this myself. Then I could also do the rocker studs.

There is a guy selling NIB e-techs. If the price is right, I may just bite the bullet and grab them ..... you thought I was kidding above

But seeing that I could sell my current heads, cam, springs/retainers and what ever else I can find laying around, the price may be justified seeing how much all this other crap would cost.

Well, I cant say from a physical standpoint because I dont know alot about how pushrods, rocker arms, valves, all that go together.

However, if this would not need machining, what I would do is probably think about running the stock cam with the 1.6 rockers (if it would work) because that saves you alot of work.

Also, the LT4 hotcam is supposed to be an absolute pain to tune for. Since you are gonna be starting at a blank, it would probably be easier with the EBL to tune for a milder cam, because you are already far from a stock TBI motor with your vortec heads and intake, and your possible exhaust mods.

"Absolute Pain" is a fairly aggressive statement to make, what is your basis for claiming this? Have you tuned an engine with an LT4 cam before? Have you tuned your engine? What are the specs of it? My point being that this is a mild combo and "pain" is of course relative. Fast355 lays out how to tune nearly this exact combo in the sticky to this forum! Don't rush it Mike, it sounds like you're getting all of your bases covered, it will be a fun car when you're done with this!

Arbor and guide cutter I have Crane version. Seals I have exact number. Valve seat cutter? You doing a valve job? Or am I not understanding?

Sorry, I am getting my terminology mixed up. The tool in mention is what you would used to cut the spring seat to the correct diameter for LT-4 springs as opposed to buying the beehives.

I seriously am considering the e-techs, especially if I determine that the vortec heads I have the hardened exhaust valve seats.

I am going to price everything out and compare them side by side.

Then I will flip a coin and either go balls out or just leave the stock cam in for now, but what fun would that be.