vortec heads

[79brent]

i have a 79 c10 shortbed and with tax season coming up i was thinking a vortec head swap. My motor is a reman 350 210hp from an 85 truck ordered from napa auto parts and has about 5k on it. I know i will need valve covers, intake and all the vortec style bolts to go with but my question is, will my factory smog manifolds bolt up to em(smog long tubes coming soon) and ive read you have to mod the throttle linkage as the vortec carb intakes dont have the bracket welded on? Im looking to build it to a reliable 350hp while keeping it looking cali street legal(my daily driver for 3 years now). carb is a rebuilt rochester its got a new 2.5" exhaust with a high flow cat and flowmaster muffler on it. also what would be a good cam with the vortec's? my rear end is a factory 2.76 ratio, tranny is a rebuilt th350 with a shift kit. i plan on changing the rear end as those gears are crap, prolly gonna be in the 3.08-3.73 range.

[1980c10]

I am not sure about the exhaust manifolds. Why not wait for the headers?
This is what i used for a bracket; sorry it was the best pic of the bracket I could find.

I found it on ebay they are pretty common and are really universal as far as hooking up a throttle cable. I am not sure what carbs they will bolt up to-mine happens to be a holley. It just bolts in with the carb. It waould also be fairly simple to modify your current bracket as well
Btw in this the engine is fully hooked up and running minus the aire cleaner. (I don't have to follow any smog or inspection rules)
Also there is no EGR provision on the intake I used(edelbrock).

[79brent]

thanks for the reply. i havent looked to see what i can do yet to modify the existing one, and ill prolly just get all the parts i need, intake, heads, headers etc and put em on once i know i have all the correct parts. As for the egr port, are you talking about the one that bolts in front of the thermostat housing next to the alternator hole? this is the only port i know about that i will not be able to use, i figured ide hook up all the other vac and egr lines and hope the smog inspector doesnt notice that one.. lol
Also would i be able to make 350hp with a stock bottom end with the quadrajet a nice came headersand those vortecs?

[79brent]

i actually just read on another site that there is no heat crossover or way to hook up the egr  . now this is gonna get me thinkin about a different set of heads with the same flow that will accept either my factory intake or a CARB legal edelbrock performer. i know about those old double humps but they do not have the accessory holes, could one maybe tap these or is there a better head you guys would recommend?
BTW i hate california for their smog laws

[jaredts]

I think some of the double hump heads did have accessory holes, just not all of them (could be wrong).  I bought a set of Summit cast iron heads for mine so I could just keep all of my existing stuff.  I'm pretty happy with the results, but vortec is a much better option as you get the flow and a significant compression jump.  If you want a little better flow and want to easily keep all of your existing parts its not a bad upgrade for a little over $600 for new heads.  I think the compression chambers are very close to stock though, so almost no bump in compression.  With a little research, I bet you can do the vortec heads and pass inspection.

[79brent]

i found one egr manifold from gm performance parts # 12496820 spread or square bore, that will bolt to the vortecs you just need the vortec style exhaust manifold to run the egr correctly.

[1980c10]

The vortech heads seem to be about 30 hp over the old 462s. They are also found in much better shape and already have the holes needed. So if you can sort out the egr issue that would be the way to go.
My 75 block 350 with vortech heads, mild cam and flat top pistons was dynoed at 393 hp at 5400rpm and 432 tq at 4300
So the same engine with with dished pistons could get 350hp but you really have to have it dialed in on that carb and whatever heads you get you'll need to upgrade the valve springs or the valves will start to float at 4000rpms. I'm not sure that you can get there with stock vortech manifolds. (I'm not really familiar with them)
I didn't look at the part# you are looking at but just make sure when you order the manifold that it is set for a gen 1 block with vortech heads and not just a vortech engine. I would also not take it for granted that it has the egr provision unless it specifically states that it does. My edelbrock showed the egr hole on the picture of the manifold on the box it came in but it wasn't there.

[79brent]

thanks for the info. what are the specs on the cam your running? and it does specifically state it has the egr, im sure i wouldnt be around 350 with those stock manifolds, i was just gonna run em until i can afford some egr headers. Is there anything else i might need to change with these heads other than what we have covered?

[muddpuppy01]

1980c10 I second the specs on your cam. With the torque peak not until 4000 rpm you duration up over 220 with 110 lsa?

[1980c10]

The specs didn't say if it had the egr or not(I didn't want it to) The only clue was the pic on the box and it was wrong.
Anything else;
You can use the stock vortech rockers as they are self aligning and you wont need to use guide rails etc.
I am running the stock replacement a/c delco platinum spark plug that was spec'd for the truck the heads came off of.
Your coolant temp sensor might not fit the head but thats a small hurdle.
I can't really think of anything else but like i said didn't have to worry about emissions and inspections so you have a little more work ahead of you than I did. In the end you'll be glad you went through it.

[1980c10]

My cam; Crower torque beast
Cam Style  Hydraulic flat tappet
Basic Operating RPM Range  1,800-5,500
Intake Duration at 050 inch Lift  214
Exhaust Duration at 050 inch Lift  224
Duration at 050 inch Lift  214 int./224 exh.
Advertised Intake Duration  288
Advertised Exhaust Duration  298
Advertised Duration  288 int./298 exh.
Intake Valve Lift with Factory Rocker Arm Ratio  0.444 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio  0.467 in.
Valve Lift with Factory Rocker Arm Ratio  0.444 int./0.467 exh.
Lobe Separation (degrees)  112
Dyno result
rpm                 tq                hp
3000           401               229
3100           405               239
3200           409               249
3300           412               259
3400           413               268
3500           416               277
3600           420               288
3700           422               297
3800           423               305
3900           423               313
4000           424               323
4100           427               334
4200           431               344             
4300           432               353
4400           432               361
4500           430               368             
4600           428               375
4700           424               380
4800           420               384
4900           414               387
5000           409               389
5100           404               392
5200           397               393
5300           389               393
5400           383               393
5500           374               392

[frotosride]

You said that you just want it to appear smog legal right? well I'm not sur how the heads are stamped with the smog codes but mostlikely they will be under the valve covers and if so then who cares if the heads have the egr port as long as the intake does. This way you can bolt on the egr valve to the intake and it "appear" stock. In Cali the biggest thing that you have to watch out for with these inspectors and replacing parts is that CARB complient smog stamp. Oddly enough most of the heads are exactly the same as the non complient ones it's just that the manufactures have to sent the parts though extra inspections inorder to get that stupid number and thus the reason they seem to cost more.

[travisr1988]

I too am doing a vortec head swap and it actually involves more than alot of people think. The stock manifolds of the '70s don't fit very well, coolant temp sensor is  different (still looking for a solution) tge springs need attention, lift is limited, intake is considerably different, use of electric or manual choke is necessary, egr is different, but given the compression jump and the better design it should pay off. My swap is held up by heat and the temp sensor.