Vortec Heads??????

[motovate]

I have a 1989 Chevy 3/4T Suburban with a replacement chevy brand crate engine.

I always thought it had Vortec Heads but I was surprised today when the 4 BBL Edelbrock Vortec manifold I bought would not fit. Big difference was the angle of the manifold bolts. The manifold I got has bolts straight up and down and the TBI manifolds bolts are angled so it would not fit.

It appears there are more then one kind of a vortec head or maybe there are TBI heads then Vortec Heads???

Has anyone gone back to a 4 bbl carb manifold from a TBI maniffold???? Or at least found a 4 bbl adapter to a TBI??????

Thanks

[Marv D]

No unfortunately many think every SBC head with centerbolt valve covers are Vortec,, not so. Vortec heads were ONLY 1996-1998 (99 saw the introduction of the LS platform,, although L31 Vortec motors extended into 2003ish in some vans, industrial applications and marine engines,,, just not production cars and trucks)

Late 80's through 95 were centerbolt valve covers, but NOT VOrtecs. They are what GM called 'Swirl Port" and .. well depending on what you are looking for and want,,,, are noted as being some of the WORST flowing heads GM ever produced.

Thing is brute flow numbers (good or bad) don't tell the whole story. Low lift port velocity is WAY more important to making low speed TORQUE than brute flow numbers. In fact most heads that make great flow numbers at .5 and .6 lift, are TERRIBLE for making decent port velocity and cylinder filling at low lift numbers, and low rpm. For a heavy truck that WORKS in a idle to 3000RPM range as is 99% of our driving,, they really are not that 'terrible' as their reputation makes out.

UNFORTUNATELY,,, the intake manifold with it's bastard bolt pattern is issue. You 'can' take and drill and elongate a early SBC intake and make them 'bolt up' to the swirlport' heads. BUT the port match is almost NEVER good. If you take the time to disassemble the heads and mark / port the heads and intake so the 'step' is the right way (instead of building a dam) well..... you've invested enough in both pieces that your $'s ahead just buying a better set of heads.

Just a FYI (And I always make enemies here) Remember the 'CamelHump' heads of the 60's???,, the Vortec heads are nothing but the 'camelhump' hype of the 90's. They are a decent head,, FOR A GM PRODUCTION HEAD OF THE ERA. But they are not any GawdSent high performance wonder of the SBC like the car magazines made them out to be.
Here is a couple of facts:
The old 186 casting used on the 1970 LT1 that was rated at 370 HP, flows 218cfm intake and 137cfm on a reputable superFlow flow bench with an as-cast 155cc intake runner

The Vortec (with a top rating of 255HP) flows 239cfm Intake on the same bench. With it's 170cc intake runner.
(HP numbers cited there just for reference,, it's a MEANINGLESS number and were rated differently in 70 than they were in 96)

Not a HUGE difference there,, and the Vortec is by far the best PRODUCTION head GM ever cast for the SBC,, NO argument there. But the aftermarket has standard 23° SBC heads flowing 370cfm (if your willing to pay the price)

NEXT fact is,,, if you had a set of Vortec heads,,, you would have to buy the $450 GMPP speciality intake to get the TBI to bolt up to them.

[Tom]

Originally Posted by Marv D

NEXT fact is,,, if you had a set of Vortec heads,,, you would have to buy the $450 GMPP speciality intake to get the TBI to bolt up to them.

Not true. Carb intake with adapter works fine for much less.
Op- Marv is correct, you do not have vortec heads.
Camelhumps were all the rage because back in the day it was the best you could get. In 1996, vortecs were the shiz nittle bam snip snap snap. Yes, these days they are middle ground as far as small block head flow goes, but for oem castings it doesn't get better. Remember they flowed as well as the bigger CC "bowtie" castings chevy sold over the counter as a performance upgrade.

[motovate]

Thanks - where can I get a tbi to carb intake adapter???

Originally Posted by Tom

Not true. Carb intake with adapter works fine for much less.
Op- Marv is correct, you do not have vortec heads.
Camelhumps were all the rage because back in the day it was the best you could get. In 1996, vortecs were the shiz nittle bam snip snap snap. Yes, these days they are middle ground as far as small block head flow goes, but for oem castings it doesn't get better. Remember they flowed as well as the bigger CC "bowtie" castings chevy sold over the counter as a performance upgrade.

[motovate]

Thanks - this sure comes under the "I wish I WUDDA KNOWN!!!! concept! Very informative and good info.

I only see a couple of options for me.

Get a good set of Vortec Heads and put those on my 89 engine and then use the Edelbrock 2716 manifold I just bought for my not so vortec engine. $$$

Get a set of earlier SBC heads - maybe camel hump or at least decent and put them on the not so vortec block - that will work correct???? I can then use one of the old SBC Edelbrock manifolds I already have sitting around collecting dust. $$$

Or find the elusive TBI to 4BBL adapters and put it on either the stock TBI manifold or the unused Edelbrock TBI manifold collecting dust and put it on the existing heads. Way less $$$$$.

I don't like the " do a bunch of grinding - trying to fit and seal choice.

All this hassle just because I want to haul water!

The situation is that I have a 1972 Chevy k20 4x4 that I got 8 or 10 years ago as a project and because I like that body style. I also like Flat Beds so I put a flat bed on the K20 and Chevy Crate 350/350HP engine in place of the 400 that broke. It was always supposed to be the "fun truck" not the work truck. I ended up in Northern Arizona and have to haul water to the house so the Flat Bed got turned into the water hauler.

Along the way I ended up with a 89 Chevy Suburban 4x4 with a newer chevy crate engine and decided to put the Turbo 350 transmission & transfer case in the 72 . Then I decided to get another truck - Chevy k2500 4x4 PU to put the water tank in and get the Flat bed back to "FUN TRUCK". Turns out the engine in the k2500 is pretty worn - no oil pressure at idle when it has warmed up - maybe 15 or so when it is running down the road. It works but.........

So here we go again -put the good sub engine with the fancy "Vortec" heads in the not so good K2500 and put a 4 bbl on because I just never liked the TBI and I've got a couple of good 4bbls.. Turns out the sub has "not so Vortec" heads!! so I've got yet another Chevy manifold ready to collect dust

Thanks - I am correct in thinking I can put either the newer actual Vortec heads or the older SBC heads on the 89 SBC engine - right???

LBM

Originally Posted by Marv D

No unfortunately many think every SBC head with centerbolt valve covers are Vortec,, not so. Vortec heads were ONLY 1996-1998 (99 saw the introduction of the LS platform,, although L31 Vortec motors extended into 2003ish in some vans, industrial applications and marine engines,,, just not production cars and trucks)

Late 80's through 95 were centerbolt valve covers, but NOT VOrtecs. They are what GM called 'Swirl Port" and .. well depending on what you are looking for and want,,,, are noted as being some of the WORST flowing heads GM ever produced.

Thing is brute flow numbers (good or bad) don't tell the whole story. Low lift port velocity is WAY more important to making low speed TORQUE than brute flow numbers. In fact most heads that make great flow numbers at .5 and .6 lift, are TERRIBLE for making decent port velocity and cylinder filling at low lift numbers, and low rpm. For a heavy truck that WORKS in a idle to 3000RPM range as is 99% of our driving,, they really are not that 'terrible' as their reputation makes out.

UNFORTUNATELY,,, the intake manifold with it's bastard bolt pattern is issue. You 'can' take and drill and elongate a early SBC intake and make them 'bolt up' to the swirlport' heads. BUT the port match is almost NEVER good. If you take the time to disassemble the heads and mark / port the heads and intake so the 'step' is the right way (instead of building a dam) well..... you've invested enough in both pieces that your $'s ahead just buying a better set of heads.

Just a FYI (And I always make enemies here) Remember the 'CamelHump' heads of the 60's???,, the Vortec heads are nothing but the 'camelhump' hype of the 90's. They are a decent head,, FOR A GM PRODUCTION HEAD OF THE ERA. But they are not any GawdSent high performance wonder of the SBC like the car magazines made them out to be.
Here is a couple of facts:
The old 186 casting used on the 1970 LT1 that was rated at 370 HP, flows 218cfm intake and 137cfm on a reputable superFlow flow bench with an as-cast 155cc intake runner

The Vortec (with a top rating of 255HP) flows 239cfm Intake on the same bench. With it's 170cc intake runner.
(HP numbers cited there just for reference,, it's a MEANINGLESS number and were rated differently in 70 than they were in 96)

Not a HUGE difference there,, and the Vortec is by far the best PRODUCTION head GM ever cast for the SBC,, NO argument there. But the aftermarket has standard 23° SBC heads flowing 370cfm (if your willing to pay the price)

NEXT fact is,,, if you had a set of Vortec heads,,, you would have to buy the $450 GMPP speciality intake to get the TBI to bolt up to them.

[Marv D]

You are correct in thinking the block will accept 1958-1996 heads. Pretty much ANY SBC head will bolt to the block.
BUT,, the early camelhump heads (through mid-year 1968) did not have accessory holes to bolt the accessories to the front of the motor,, The later (186/187 and 492 castings of midyear 68- on did) so Camelhumps,, while will bolt on, will not make you very happy as you start to bolt things up underhood IF they are the early version. Not to mention, they did not have induction hardened seats that is more friendly with unleaded fuels, and 99 out of 100 'camelhump' heads will be in SERIOUS need of a complete rebuild (which you can spend a ton refurbisihing a older set of heads) ,, and that's IF they are not full of cracks radiating out of the exhaust seat.

Honestly,, aside from a backyard find of someone that has had a set of decent heads sitting around and is just wanting to get rid of them.. for your carb motor (and as much a I HATE to promote buying the cheap chineese import crap... THESE are probably the most economical way to get a complete, fresh, uncracked 70's style head with accessory holes.

BUT first thing I'd want to ask here ....... Have you VERIFIED the K250 really has no/low oil pressure. the gauges and sending units in these things are always suspect! As is a mechanical gauge that has had the tube pinched off my a overzellous wrenchtwister. A mechanical gauge connected just to verify hot oil pressure may save you a pile of cash you just 'thought' you needed to spend.....

[motovate]

Thanks. Learning more all the time -your right I would of not been happy to find the camel humps not fitting the accessories. I actually saw those heads in the summit catalog but didn't read all the info you are right the price is hard to beat.

Well as far as verifying oil pressure I actually took the truck to a shop to have it checked out and fix the steering. They replaced the oil pressure sending unit and made sure all the gauges worked except the speedo. The gauge showed low pressure maybe 15 psi but steady until I started hauling water and it warmed up to operating temp. Then the check gauges light started coming on @ idle and the gauge dropping to zero but as rpm increases the light goes out and gauge comes back up - no clatter though. I put some motor honey in to see if it would thicken up the oil a little - it worked - a little. It really was a choice of knowing the old engine had at least 200000 miles on it and the Suburban crate engine had less then 28000 miles on it , I know it from the beginning and it has real good oil pressure. So put the good engine in and quit worrying about it.

I just started thinking ( not always a good thing) got hung up on 4bb vs tbi and wanted to go back to a carb because I was looking at a 64 Chevelle and thought I could just pop the sub engine in it and stick the 4 bbl and go. Then I started thinking about the k2500 and being practical . At this time I'll just stay with the Tbi. Whats left of the sub is about to go away and I won't have a good engine staring me in the face whispering "what about me". At least I know now what I'd need to do if I try to get rid of the TBI and go 4 bbl at some point in the future.

Originally Posted by Marv D

You are correct in thinking the block will accept 1958-1996 heads. Pretty much ANY SBC head will bolt to the block.
BUT,, the early camelhump heads (through mid-year 1968) did not have accessory holes to bolt the accessories to the front of the motor,, The later (186/187 and 492 castings of midyear 68- on did) so Camelhumps,, while will bolt on, will not make you very happy as you start to bolt things up underhood IF they are the early version. Not to mention, they did not have induction hardened seats that is more friendly with unleaded fuels, and 99 out of 100 'camelhump' heads will be in SERIOUS need of a complete rebuild (which you can spend a ton refurbisihing a older set of heads) ,, and that's IF they are not full of cracks radiating out of the exhaust seat.

Honestly,, aside from a backyard find of someone that has had a set of decent heads sitting around and is just wanting to get rid of them.. for your carb motor (and as much a I HATE to promote buying the cheap chineese import crap... THESE are probably the most economical way to get a complete, fresh, uncracked 70's style head with accessory holes.

BUT first thing I'd want to ask here ....... Have you VERIFIED the K250 really has no/low oil pressure. the gauges and sending units in these things are always suspect! As is a mechanical gauge that has had the tube pinched off my a overzellous wrenchtwister. A mechanical gauge connected just to verify hot oil pressure may save you a pile of cash you just 'thought' you needed to spend.....

[Tom]

The heads on the engine now won't make any less power then 98% of the other heads out there that aren't vortecs. There's no point is swapping them unless you get better castings, and oem's aren't gonna cut it.

[motovate]

Or of course if your not looking for max power but just want to dump the TBI and put on a 4bbl manifold. I still can't find a TBI to 4 bbl adapter , I can only find 4bbl to TBI adapters so changing the heads seem to be the only way to mount a 4 bbl manifold. Or of course just leaving it as it is and go take some asprin is a choice. LBM

Originally Posted by Tom

The heads on the engine now won't make any less power then 98% of the other heads out there that aren't vortecs. There's no point is swapping them unless you get better castings, and oem's aren't gonna cut it.

[Tom]

Carb onto TBI manifold? Won't happen as the TBI is only 2 barrel. A simple google search shows http://www.jegs.com/i/Edelbrock/350/...oductId=745125

[motovate]

Thanks- I talked to Jegs to be sure and that will do the trick but I went with a Weiand 8126 same fit and less $ - I never looked at that one because it has the old Quad Jet carb opening but it is also drilled for and supposed to fit the square flange Edelbrock carb I already have. I guess we will see in a few days when it gets here.

LBM

Originally Posted by Tom

Carb onto TBI manifold? Won't happen as the TBI is only 2 barrel. A simple google search shows http://www.jegs.com/i/Edelbrock/350/...oductId=745125