IHI

iTrader: (1)

Tried to search but could'nt find the answer I was lookin for. Right now I have a set of Vortec ordered up. They are already ported and I'm buying the intake/header gaskets with them as well to have them port to the gaskets as well. Heads are already machined and come with screw in rocker arms and guide plates, come ready for a .600 lift cam, but having softer ones installed since mine is only gonna be a .515 lift hydralulic, only shootin for 12.0's for ET finals. Anyways, tryin to get all my duckin in a row and need more info. I'm currently waiting for an answer to see if they can drill the ehads to accept my older style valve covers to save some $$$ instead of buying new ones-has anybody done that before. Second question, I'm currently running aluminum Proform roller rocker-2nd year-and need to know if I can just unbolt them from my current heads and reinstall onto the vortecs with no problems. I keep seeing rocker arms advertised with "narrow body". I don't want to get ready to bolt this thing together and have something like that stop me from completing my swap. Since this is only gonna be a 1 race swap I'll just buy the cheap GM stamped, self-guided arms, so if I have to go that route since the heads are already machined to accept older nonguiding arms, will this screw stuff up again? I've tried to gather as much info as possible in the past week before I decided to do this, but am left with these few unanswered questions. Bought a Edelbrock RPM Air-gap manifold to fit the Vortec heads if that makes any difference. Hate to spend $300 for arms for 1 race, since this will probably just get stuffed in the corner for back-up so it won't be money wasted I guess if I need to go that route. Hey, any experience/input you have to offer is apprecietated.

Pony Killer

first off bout matching the heads to the intake to the gaskets..

The factory gaskets, and factory style gaskets.. the gasket ports are so much bigger than the head ports that gasket matching them isn't a good idea...

as far as the vavle covers go... i'm using a stock set with mine... stock centerbolt vavlecovers off an RS. got them for nothing... you could probably do the same or get a set for 10 bucks from a bone yard and clean em up.

you need the narrow body rocker arms, since your running guide plates no need for the self aligning ones. I'd got with a set of cranes race golds. I have them... like them alot..

although i'm running the narrow body self aligning ones.

As far as running 12.0's it's very do-able with a reasonably mild cam.. I'm running a comp hydraulic flat tappet XE274 cam with mine.. on 1.5 rockers.. ending up with sub .500 lift. and could run 12.0'-.1 @ 112 at will with it.

kfoley

Since it's only for one race and then it's a backup motor I wouldn't spend that much for the Crane gold rockers. Sure they're nice, but unnecessary in this case. A set of GM or crane/summit stamped steel rocker arms will work fine. In fact you could go with the 1.6 ratios for more lift since they're the same price. Good luck with it!

IHI

iTrader: (1)

Alright, i'll pass on the Cranes since a bigger motor is in the near future. Got my eye on some valve covers E-bay has to offer with some flare, so we'll see what the guy has to say about drilling for older style covers. Now am I right to assume I can just buy the old style factory stamped rocker arms WITHOUT the self guiding tips? As far as the 1.6 rackers go, will I have to drill out the pushrod holes in the head to compensate for the geometry of the increased lift of the 1.6's. I've heard mixed results of these bigger arms, some guys that did dyno pulls here picked up a few ponies, while the guys that did "track testing" did'nt notice anything. So if it requires me to drill the holes I'll probably just stick with normal 1.5's since the gains don't sound that large. I have 2 more points races coming up and want to do a test to se what kind of gains these heads are worth before I swap cams and go to Nationals. Currently running 305 cast iron heads with bigger 2.02/1.60 valves, and 170cc runners-no port work. My cheap combo is good enough for 12.9's at one track and 13.0's at the other. My current cam is in my sig and I'm just wondering by switching heads and jumping up to the 300/300 .515/.515 Lunati cam is gonna net enough umph to motivate my 3420 heavy weight .9 quicker. Pony killer got me all excited by his remarks, so I'm definatley looking forward to this experiment. I guess I'd like to see that just by swapping heads/intake I could get into the 12.5's and then letting the bigger cam take care of the other .5. Hey thanks for the info and any other remarkd are apprecieted,

OMINOUS_87

Very good info, do not hog out to a factory gasket, you wil ruin the heads.

Feel free though to gasket match a Felpro 1255, thats what I did. They are not factory type gaskets, they match the port shape very well.

AJ_92RS

I have a pair of stock covers that are in pretty good shape.

Shoot me a PM.

You pay for shipping and they're yours.

Dyno Don

iTrader: (7)

There is no material to drill the bolt holes for early covers, but they do make an adapter that bolts to the head so you can use the early covers


[I'm currently waiting for an answer to see if they can drill the heads to accept my older style valve covers to save some $$$ instead of buying new ones-has anybody done that before. ]

kfoley

If you have guidplates you can run non-SA rockers, which if I read correctly above you have guideplates, so those rockers will work. Some people have to drill the holes, others don't. I've known people running the hotcam (.525 lift w/1.6 rockers) on vortec heads and not have to touch them, however I wouldn't bet on it. Course drilling them isn't all that hard either, especially if the heads aren't on the motor yet. It probably takes 10 minutes to drill them all. The difference between the 1.5's and the 1.6's isn't alot, probably around 15hp or so. It wouldn't be worth changing out perfectly good 1.5 rockers for, but since you're getting new ones and they're the same price you might as well go with the 1.6's.

IHI

iTrader: (1)

AJ, I'm gonna buy a set off E-bay that are chrome for the extra flare, but thanks anyways.
The guy e-mailed me last night and did confirm I'd have to run the newer valve covers, but he's saying I can reuse my old roller rockers as long as they take a 3/8" stud, which they do. What is the reason older style rockers cannot be bolted on? Are these Vortecs redesigned from traditional heads and the studs closer together that mount the rocker arms? I mean, why could'nt I reuse my old roller rockers, is there something that pyhsically does not allow this? As far as drilling the pushrod hole if needed for a 1.6 rocker, would I need to buy that jig to get the correct angle, or just hog it out a little bit?
Thanks again for quick responses, I'm gonna shoot another e-mail back with the Fel-Pro p/n just so they don't fubar the heads on a factory gasket match.

poncho@home

As far as the valve covers goes. My brother had his vortec heads modified for early style valve covers. Cost alot more than buying used centerbolt covers. He did because his heads were going into an 1981 Z28 and he didn't want it to look like a later model motor was in there....he's **** about attention to details.

They had to weld material onto the heads to drill and tap for the early style valve covers. Not that many people can weld cast iron, luckily up here in Quebec these talents are plentifull!!!

Find yourself some used centerbolt valve covers...

kfoley

You don't have to get a jig to elongate them. Just use the proper sized drill bit (the width of the pushrod hole) and take some material off the ends of the hole. I think the reason they were saying you can't use the old roller rockers is because they are not-SA and the new vortec style heads require SA rockers unless they have guideplates installed.

Pony Killer

The wide body rocker arms... the standard type for the perimiter v/c heads tend to hit the bolt tubes for the centerbolt covers... for the retaining bolts... and all hacking the tubes off does is cause an oil leak.


As far as the 1.5/1.6 ratio debate... factory out of the box vortec heads and even ones with bowls blended lifting the valves past .520 is pointless. that's their peak flow, intake and exhaust... the intake peak might actually be a bit lower around .500. food for though

IHI

iTrader: (1)

I just talked to the shop this afternoon to go over what I want done to these heads. As stated they are already ported w/ guide plates and studs, they're going to install a lighter spring as right now they are set-up for a .600 lift roller cam and all I'll have the rest of this season is a flat tappet so the new springs are going to be good to a .575 flat tappet cam. Since the new springs are being installed he has to machine down the guide so the OD is smaller to allow the spring to fit over it and he says as long as were machining these heads would I be interested in going 2.02/1.60 valves, so of course I said yes. We're going to omit the exhaust gasket port match and just do the intake gasket port match. All siad and done at my door is $700, only $50 more than we first talked about. Oh, he's going to flow test these heads for me and send the sheet along with it. I've got other info off the net that these heads flow 230cfm out of the box, so with the port work and bigger valves I'm curious to see how gain I'm actually getting. Like I said, I'm leaving the block all the same except for the .015 head gasket to see what actual gain I'm getting over my current untouched heads-305 casting with 2.02/1.60 valves. 170cc runners. Hope it's enough to bolt on and get into 12.5-12.90 consistent territory. Then this winter I plan to build a very nice 383 short block and roller cam set-up to install these heads on and see what I end up with. Very anxious already but now with the added maching have to wait an extra week.

OMINOUS_87

Cool man, thats some good news. Make sure though ample work is done to the exhaust ports as they are the weak point of the Vortec head. Check out this article.

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

http://www.hotrod.com/techarticles/66278/index.html


The 383 will be awesome. I am running a 383 with ported E-tec 170 heads and a Superram setup on top. I am in the process of breaking it all in but I can say that she thumps pretty hard so far. I actually am just now wrapping up the install of my new exhaust which consists of Hooker coated LTs custom 3" y-pipe and a Mufflex/Spintech 3.5" muffler setup. Should have her back on the road this weekend.

IHI

iTrader: (1)

Super tech articles, glad you posted because I could'nt remember which magazine had what-kinda all look the same after you read them all 100X's After reading again, I have no doubt that I will see high 11's next season and then this car will finally be done and I can get a race only vehicle.

iroczman380

They may be the weak point of the vortec head but even with that week point they still made nearly 440 horse at 5300 or whatever. ID say that aint to bad. but hey i already had my vortecs upgraded with the 1.6 valves and exhaust work done to them so Im hoping i can get close to 500 ponies since Ill also be running a 383 and not a 350,. Just my 02


IROCZMAN380