vortec on a gen 1 small block questons.
 

so im on the lookout for heads for my truck, and i have been thinking about the vortec heads.. but a have a few questions about them.
1. will they work on a gen 1 small block?
2. will i need to get a different intake?
3. what other differences are between them and the gen one heads that will effect me?
thanks,

Re: vortec on a gen 1 small block questons.
 

The 350 engine will take a set of vortec heads, as I have put a set of 96 vortec heads on a 350 out of a 90 corvette and they fit right up. The intake bolt pattern is different for the vortec heads and the right way is to purchase a different intake that aligns the holes properly. Many have taken the old intakes and reworked the center holes so that they can put the bolts in at the different angle than the older heads used.

The flow characteristics of the vortec heads is significantly better than a standard Gen 1 head.

Re: vortec on a gen 1 small block questons.
 

you have to get a vortec intake..reworked 55-86 in takes will only work if you using 87-95 heads..vortecs are a different animal.

Re: vortec on a gen 1 small block questons.
 

That is a fact. Vortec intakes don't even have the center bolt holes. Just the pairs on the ends. It's a whole different animal.

Other considerations....

-You have to have self aligning rocker arms. You can get them off any center bolt head or vortec head engine or buy new.
-Obviously different intake as discussed above along with the vortec specific intake manifold bolts and gaskets
-Center bolt type of valve covers and gaskets

Re: vortec on a gen 1 small block questons.
 

Another thing is that you will not be able to run any type of factory stylr hot air choke on your carburetor. You will be limited to an electric choke or a manual choke.

The Edelbrock Performer RPM Vortec intake, has provisions for running coolant under the carb, whereas the Performer does not. This will help keep the carb from icing up in colder climates.

Re: vortec on a gen 1 small block questons.
 

What type of rocker arms do I need?? Can I still use my push rods?
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Re: vortec on a gen 1 small block questons.
 

You need self aligning rocker arms.

Re: vortec on a gen 1 small block questons.
 

So I picked up a set of junk yArd vortecs today, and the push rods are shorter in the vortec heads over my other rods, which do I use??
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Re: vortec on a gen 1 small block questons.
 

Use your original pushrods. The vortec engines are roller cam engines which have taller lifters and consequently shorter pushrods to compensate.
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Re: vortec on a gen 1 small block questons.
 

Thanks a million! This is all new to me.
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Re: vortec on a gen 1 small block questons.
 

You're very welcome my brother. I'm not as versed on newer stuff as I am older but I have run into this situation before. Any further questions just ask. I'm sure someone here will be able to help.
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Re: vortec on a gen 1 small block questons.
 

one more question, today a buddy of mine told me that i had to drill a 5/16 hole for the water flow. anybody know anything about this?

Re: vortec on a gen 1 small block questons.
 

I got a releated question. On a 350 (early, like 1969 block) the oil dipstick runs through the drivers side of the engine block and the 350 oil pan has a little relief that sticks out so the oil dipstick runs into the pan there. Does that all get covered up with the Vortec Heads? If so, what oil pan do you need to use?

Re: vortec on a gen 1 small block questons.
 

He is likely referring to the thermostat bypass hole. The Vortec heads do not have that hole drilled in them, as the Vortec engines use a different style of bypass. The couple engines I have installed Vortec heads on, I did not know about the hole not being there. So consequently I did not drill the hole. I haven't noticed any issues with those engines, but the next time I install a set of Vortec heads, I think I am going to drill that hole. You can find where is comes out on the deck surface, by running a wire up thru the bypass hole on the water pump mounting surface. You could also accomplish this with compressed air.

Some guys say to just drill a couple small holes in the thermostat itself. Maybe two 1/8" holes.

Re: vortec on a gen 1 small block questons.
 

The Vortec heads will not affect the drivers side dipstick. Externally they are not physically any larger than any other small block head.

Re: vortec on a gen 1 small block questons.
 

im in the prosses of building up the 350 i pulled out of my 87 the only vortec heads i could get my hands on was off a 305

what kind of numbers can i expect with a 350 bottom end and a 305 top end

all i read about is how crapy these heads are and if your gana go vortec go with the l31 heads but the l30 heads do flow better then the swirl port tbi heads and the compression helps

Re: vortec on a gen 1 small block questons.
 

You wouldn't happen to know if this is on all vortec heads or not? Because I compared the face of my vortec to my stock head and all the ports on the face are the exact same.
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Re: vortec on a gen 1 small block questons.
 

The #3, 4, 5, 6 spark plugs are slightly closer to the exhaust ports. Depending on what headers/manifolds you run, you may run into clearance issues.

When i did this swap, my shorty headers that worked fine on stock heads did not work with vortecs. I did not catch the issue until it burnt my plug boots and was shorting all 4 plugs.

You may be fine, but check before you make the mistake i did.

Scorpion makes a good full-roller, self aligning rocker.

Vortec engines are notorious for leaking intake gaskets. Dont use the stock gaskets, use the gaskets they install when doing a recall repair. MS98000T.

If you are going to run bigger valve lift than .480" you need machining. Flow tapers off after .540" of lift in a stock vortec head. Stock GM springs NAL-12499224 are behive and similar to the expensive comp cam springs. Comp Cam spring retainers CCA-774-16 can also be used with these springs to gain retainer-seal clearance.

Re: vortec on a gen 1 small block questons.
 

The Vortec heads are the 062 and 906 castings, not any head that had the "Vortec" name on them.

I did drill a single hole in the thermostat, but I believe that the waterpump has a bypass built in and the hole wasn't needed. (memory from something I read). I know I changed the thermostat and didn't drill it with no issues.

Re: vortec on a gen 1 small block questons.
 

When you say "all the ports on the face are the exact same", where are you looking? the exhaust side or intake side? I'm talking about on the deck surface of the hears. Every OEM Vortec head that I have seen, did not have the thermostat bypass hole.

Re: vortec on a gen 1 small block questons.
 

The water pump does have a bypass hole on the passenger side of the pump. It is a small hole ( about 3/8") below the main hole. That hole matches up with a hole in the block, that comes out on the passenger side deck surface of the block. With the Vortec heads not having that hole drilled in them, that bypass is essentially blocked off.

Re: vortec on a gen 1 small block questons.
 

Thanks Captainfab, My memory isn't as good as it used to be.
Like you, I had run without the hole and no issues.

Re: vortec on a gen 1 small block questons.
 

i was looking on the deck as well. i had the valves facing me, and by ports i meant water jackets.

Re: vortec on a gen 1 small block questons.
 

I'll see if I can get a couple pictures tomorrow.

Re: vortec on a gen 1 small block questons.
 

I ran into the olderblock not having the water passage. I had to drill my block.
My vortec heads are after market, but here is what I found...

http://67-72chevytrucks.com/vboard/s...d.php?t=336204

scott