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96Dually 07-27-2012 04:52 PM

Cam Choice
 
Ok, I know its ols school, but just getting some opinions.

I'm building a low budget 350 for my 77 Z28 for now. I was porting on an old set of heads but I aquired a set of 062 Vortecs.

1 Main Question, I bought a while ago the old L79 cam, yes I know better out there but....... which to choose?

Short block just a good runnin mid 70s vette / camaro 350 I had , stock
dished pistons etc.

2. Opinions on Vortecs ?

3. Any dyno or ET results with similar combos?

Too busy to mess around with experimenting, so figured some fellow gear heads could help.

vinniekq2 07-27-2012 07:14 PM

sounds like a 300 hp combo

Huneycutt 07-27-2012 07:18 PM

Be careful with Vortecs. They are good heads but use a different bolt pattern for the intake and (I think) exhaust manifold. You can wind up spending a lot more than you planned if you don't already have all the other stuff you need to go with a set of Vortec heads.

bigdog7373 07-27-2012 07:23 PM

Yup intake is different. Same exhaust though.. Ignition timing will be a little different though so make sure you read up on it.

LATECH 07-27-2012 07:58 PM

Heads will fit the old intake. Center bolt holes for heat riser arent present on the heads.
Look at the summit SUM 1103 cam. It looks like it will work with those heads nicely in a street application, with stock torque converter and tall rear gears. SUM 1103 Lift is also close to what the vortec max flow/lift specs are too. budget priced too. Just a thought.
Iread somewhere that the vortecs also have a factory 3 angle valve job. Probably what helps the flow numbers as a stock unit.

LATECH 07-27-2012 08:02 PM

How deep is the dish on your slugs?

96Dually 07-27-2012 08:05 PM

Cant remember on the pistons... been a while, they are just factory.
Car is 4 speed with 3.73s

LATECH 07-27-2012 08:23 PM

Lots to consider when choosing a cam.
I am thinking flat top pistons would be better as it would raise your compression ratio .
Those heads have a nice size quench pad.
You should read through the past threads by doing a search for related topics. There have been so many threads on exactly your subject.
many factors apply to choosing a cam.
You have a lot going for you allready with the 3.73 and the 4 speed manual.
Search through the database here.
I made my recommendation based on a auto trans equipt machine with a tall rear ratio, thinking yours was pretty much stock. My bad.:D

LATECH 07-27-2012 08:25 PM

Also search for the term "quench" and any post you read by a guy named techinspector, you can pretty much take as gospel

BigEd36 07-28-2012 12:01 AM

96dually, your 350 short block with factory dished pistons, plus vortec heads is the setup GMPP uses for the 350 HO (350CI 330HP) and CT350 (350CI 350HP) circle track crate engines with GMPP cam #24502476 (.435/.460, 212*/222* @ .050, 112 LSA), available for $112.95 at GM Performance 24502476 - GM Performance Hydraulic Flat Tappet Camshafts - Overview - SummitRacing.com. The Summit K1103 cam recommended by LATECH (.442/.465, 272*/282*, 214*/224* @ .050, 112 LSA) has just a bit more lift and 2 degrees more intake/exhaust duration @ .050 than the GMPP cam, so it would probably work fine with your vortec heads. The GM cam should certainly work as GM uses it with the vortecs. A Performer RPM or Weiand Stealth with 650 CFM carb should put you in that 330-350 HP range. The cam grind gives a wide, flat torque curve, & would work great in your Z28. It has a noticeable idle so you can "hear the cam", but has great street manners and plenty of vacuum for power brakes. Here's the GMPP dyno chart for the 350HO, and a YouTube video so you can hear what the combo sounds like.

http://i29.photobucket.com/albums/c2...Dyno-Chart.jpg


grandpa01 07-28-2012 12:42 AM

The intake manifold bolt holes and ports do not line up with older manifolds

cobalt327 07-28-2012 01:25 AM

Vortec heads require a dedicated Vortec intake manifold. Older manifolds have a different bolt pattern and the Vortec intake ports are considerably higher so the older intakes cannot be ported to work except for a few raised port single plane 'race' intakes- which you do not want anyway (single plane that is).

The L79 cam wants a lot more compression than you will have. The Summit cam LATECH recommended and BigEd36 talked about above is certainly worth a second look.

Quench info.

Vortec head info.

Here are a pile of dynoed combinations, some w/Vortec heads. You might find something close to what you are proposing.

96Dually 07-28-2012 08:11 PM

Thanks guys. I'll check into those other choices.
As far as compression, I was going to cheat and use a set of the 305 H.O. heads I ported.
Not lookn to spend alot in this combo, wanting to either build 377, or go LSX.
All my buddies tryn to get me to convert. Im old school.

vinniekq2 07-28-2012 08:22 PM

a modified set of vortec heads that are exhaust side ported can take you to 500 hp reguardless of what short block you use.366/377/383/

F-BIRD'88 07-28-2012 09:02 PM

the old 327 350 hp cam was made for 11:1 cr.

it works best with 10:1+ cr.

the whole thing will work a lot better with a cheap set of flat tops installed.

if useing the 305ho heads be generous with the porting and they will work well.

use a isky 270 mega cam 201271


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