1979 z28 350

Hi, just bought this z28 5.7L 350 4spd manual, so i may be posting here regularly now. I know next to nothing bout engines, mods, etc so ill be exploiting all yours expertise and your yearning to show it off!

anyway, the car is all stock and i dont have to money right now to be putting into it but soon enough I will - so i ask now: being the 79 z28 only has 175 HP stock (i forget the torque) what would you start out with to bring the power up, but without dropping 10 grand into it. If you can give me some price ranges too i'd appreciate it.

-mike

welcome dude....

well start off with the basic stuff, like exhaust.. get some headers and some good flowing tubes.

also intakes are pretty cheap. look at getting a new intake and carb. then start to dig in that engine, and get into the cam and heads... bottom end, and things like compression blow on those cars, so things like pistons would be a good thing later down on the road...

but like i said, basic stuff first... intake and exhaust.

headers - $125
good dual exaust - price will vary
Edelbrock RPM Air Gap intake manifold - $200 (i dont know for sure that it will fit under the stock hood, im sure someone here will chime in on that)
Carb, if you plan on driving it on the street, IMO you cant beat the Edelbrock. they run about 200-275 bucks

while not a power increasing mod, a steeper gear ratio is a great mod. if your gears are under a 3.23 to 1 ratio i would DEFINETLY upgrade this can run from 250 to 750 depending on if you install them and what brands/ratio you go with

The first thing to do is get a set of headers, convert to true dual exhaust and a pair of performance mufflers. Not only will you get a noticable improvement in performance, it will sound a hell of alot better too :cool: You could just get mufflers or headers, but it will be cheaper to do the whole thing at once.

If your car doesn't have posi, get it next.

Next would be an aluminum intake manifold such as the edelbrock performer and an edelbrock 650 carb with an electric choke. With the manifold/carb swap you'll also need a new air cleaner assembly, so you might as well get a K&N drop base. Clearance will be very tight so you'll probably need the shortest filter available. The throttle linkage will also become an issue, so expect to buy an aftermarket one.

The intake/carb swap is something you can do yourself, even if you've never done anything like it, so grab a haynes/chilton manual and dig in!

Next would be a cam/heads swap. Vortec heads are inexpensive and damn good. Combined with the right cam and you'll easily be making 350hp at the crank, or about 270 at the wheels and you'll be running mid-high 13's at a little over 100mph.

"convert to true dual exhaust"
how is this opposed to the dual exhaust it has now.

As far as the mufflers and headers go, this is pretty basic but what brands do you suggest.

I had mac cold air intake on my last car, I can swap it to this one - would this be a good choice for it?

Is it posi rwd or not? someone must know, i haven't lit them up yet. I assumed it was though. How much would it cost to convert to it if its not.

oh yea, and what would be the "right cams" to go with vortec heads, and whats are the gear ratio's to choose from and which being a better choice.

-thanks

not to be annoying but

::bump::

In stock form the exhaust system begins with a pair of heavy cast iron exhaust manifolds. The exhaust is then carried by a 'y-pipe', which joins the two exhaust paths into one. Shortly before the exhaust exits your vehicle, it is split again into two pipes. A true dual exhaust has 1 pipe for each manifold/header. Crawl under your car and have a look, you'll see what I mean.

For a gear ratio, 3.42:1 works quite nicely for a street driven car.

Your car has just one camshaft. As for a suitable one for vortec heads, there are much more knowledgable guys out there than me, so I'll let someone else take that one :)

For mufflers, it really depends on the sound you like... I have Flowmasters on my car, and like them. Other people swear by Dynomax.

The easiest way to tell if you have posi or not is to mash the gas and leave a little rubber on the road. It's also the most fun :)

Your Mac cold air intake won't work on your 'new' ride. Removing the rubber seal at the cowl (between hood and winshield) might get a little more cold air into your engine.

I don't know the cost of converting to posi. If you do get the conversion done, budget a little extra money incase you need new wheel bearings, and or axels.

well, the "right" cam and gears are kinda dependent on you and what you are doing with the car. if its your daily driver, then you might not want to get too wild with it. but what one person calls way too much another calls just enough.

what do you plan on doing? driver? drag car? weekend toy? whats your budget? do you drive lots of highway? only city?

one thing i have learned over the years, is that the keys to being happy with any engine you put together, is to A) be realistic with your goals (ie, dont build a hard core drag car and expect it to be easy to live with on a daily basis, or build a good driver and expect it to run 8's) and B) match the components you get with each other. (for example dont take an intake made for super high RPM and match it with a tiny cam made for low RPM) The Edelbrock packages are a very good way to do that for the beginner. Holley makes a couple of packages also. research is the best way to determine the best set up for your tates and use

easy way to do this on an engine already in a car, is to get a plan together, and map out what you want to do before you get anything, and dont stray from the plan. this way, in the end, youll have a good matched package, even if along the way you dont have the optimal setup. (of course if you plan to stratch the build out a bit, new parts will pop up, and may fit your plan better than what you had originaly intended to use)

oh, just to add, vortech heads are limited in cam lift to .480 inch lift cams. dont get one any higher than that unless you get the heads modified. I know some places sell them set up for higher lifts....

Greetings and welcome to the board :D

Since my car was stock not too long ago, I can give a little advice on what to do.

As was mentioned, you'll want to upgrade the exhaust. Personally, I prefer flowmaster, but others disagree. *shrugs*
Other things you can do, is upgrade to headers, the intake manifold, and do some suspension things.

Now, since your car is a Z28, you already have a posi rear-end, unless some nitwit specially ordered it from the factory WITHOUT it. All Z's came with posi.

For headers, the market is a wide place, but I've got Hedman headers. Picked them up off of a club member, so I can't give you any info on them.

Right now, I'm still running my stock intake manifold :cry: but I'm going to be upgrading to an Edelbrock Performer. The one that goes from idle to 5500 RPM.

Anyways, get some pictures taken! :D Can't wait to see it. Though our cars were rated at 170-180 hp, it doesn't mean they'll put out anywhere close to it. ;) Wanna see what I mean?

http://camaroz28.cardomain.com/id/1979camaro

133 hp... *dies*
That's before the engine blew up on me and I had to swap in another 350 though. Hopefully I'll get a dyno sheet on my new stuff in a few weeks ;)

Ah well, get pics up!@

How many miles are on the motor? Does it smoke? I would assess the bottom end of the motor before going crazy with Vortec heads, new cam etc. If the engine is still strong then the head swap, intake-carb, cam, exhaust would give you alot more power. However, if the engine is tired (smokes, little power etc) then a rebuild ($$$) will be necessary. Has it been tuned lately (cap, wires, plugs etc.)??

BTW, if you go with the Vortec heads I think Scoggin-Dickey sells the Vortec package (heads, rocker arms, intake manifold etc.) for around $750. Summit/Jegs sell standard 1 5-8"" Hedman headers for around $120. A good dual exhaust (custom) system (2.5") w/ an H or X pipe will cost btw. $400-800 (at least it's around that range here in RI). I like Holley carbs, a Holley 600 (vac. sec) would work well. If you have a 3.42 posi rearend then don't change it (like Erik said it's a great all around street ratio). A good cam for the Vortecs would be the Comp. Cams XE262 or the 268H (Hi-Energy).

Good luck w/ it!!

thanks guys, the suggestions were a lot of help. I basically wanted some good names and to know what not to do, which is what i got. I did some research on some different brands and I think i came up with something of a plan.

I think ill be starting off with :
-The true dual exhaust system, ill figure out which brand at the shop
-Edelbrock Performer Air-Gap (Idle-5500 RPM)
-Edelbrock Performer RPM Cam

Then:
-Headers (not sure which yet)
-Edelbrock Thunder Series AVS 650cfm Carburetor w/ electric choke
-K&N Air Filter (the reuseable ones i had one on my stang) and assembly

Ill be happy with this for a while and then l start digging in the engine more one day when i have more money and time.

By the way, yea i lit them up earlier today to see if it was posi n sure enough, i just dont like to do it on a new car dont ask me why (as if the tires will blow out the first time i decide to).

Oh and I bought it with only 60k miles on engine, it was rebuilt I think like 12 years ago by the original owner who is my friends uncle, who then only used it as a weekend car during summer until he gave it to my friend's brother 6 months ago, and now i bought it for 2k. I thought it was a great deal being everything looks close to immaculate interior and exterior -wise. I did a compression test on the engine before I bought it and everything was good.

And I do plan on using it like an everyday car, Im not going crazy to the point im getting horrible mpg and my engine is being beaten on, but just wanna give it a little more power than the 175 measly horses to go along with its strong look and name.

thanks guys.

oh yea, one other thing i wanted to ask

whats the point that you have too much power for the stock tranny and anything else that might be affected by added power.

I would try the Edelbrock heads, I think they are the best HP for the money. Headers, intake and cam next.

Originally posted by xItsMike
By the way, yea i lit them up earlier today to see if it was posi n sure enough, i just dont like to do it on a new car dont ask me why (as if the tires will blow out the first time i decide to).


Like I said, ALL Z's came with Posi.. :D :D

As for the transmission, it all depends. Personally, I wouldn't go more than 350-400 HP before you'll want to think about beefing it up. Anything below, is safe. Once again, that's all my personal preference, so don't come shootin me if your tranny breaks with 349 hp ;) :D

ya, "today" being before you said this or I read it (insert appropriate smiley face here).

and I know i wont be going over 350 HP, and probly not much over 300. So thanks thats what i needed to know.

Originally posted by xItsMike
I think ill be starting off with :
-The true dual exhaust system, ill figure out which brand at the shop
...
Then:
-Headers (not sure which yet)


get the headers when you get the exaust, otherwise youll be paying for them to redo the exaust to mate up to the headers when you get them.

o right i knew that

ima get some pics up soon before it goes to the shop for exhaust system, so i can do some before/after.

I think I'm gonna go with a dynomax exhaust system cus of the easy install and like somebody said earlier, half the ppl swear by dynomax the other half flowmaster.

Make sure you do your homework before you buy a intake manifold. I don't think the air-gap will fit under your stock hood. I had a 79 z-28 and it had a torquer II single plane intake. The wing nut was touching the hood, i tried to put a drop base air cleaner on but it woudn't clear the linkage on the carb. I think the performer will fit but i'm not sure about the performer Rpm

Originally posted by xItsMike
I think ill be starting off with :
-The true dual exhaust system, ill figure out which brand at the shop
-Edelbrock Performer Air-Gap (Idle-5500 RPM)
-Edelbrock Performer RPM Cam

Then:
-Headers (not sure which yet)
-Edelbrock Thunder Series AVS 650cfm Carburetor w/ electric choke
-K&N Air Filter (the reuseable ones i had one on my stang) and assembly



I agree with ZX about the Air Gap intake. I'm pretty sure it won't fit under the stock hood. Also, don't go with the RPM cam. It's an old school design with lazy ramps. The cam I recommended earlier, the Comp. Cams 268H (Hi-Energy) will make more power, idle better, and be MUCH better all around than the RPM cam. I've seen the 268H cam run in a few 350's and even 400's (SBC's) and believe me it's a tremendous cam (specs- 268/268 duration - .454/.454 lift). Chevy Hi Performance magazine even tested the 268H cam vs. the new XE268 cam in a mild 350 like yours and the 268H made 10 more HP and more TQ!!

Check out nastyz28.com (ALOT of information on 2nd gen. Camaros there - "High Performance" and "Engine Topic" message boards). Someone there could even run a ddyno or E.A. and compare your motor w/ the two different cams - 268H vs. RPM (HP and TQ #'s). Good luck!!

thanks im registered on the other forums now too.

I have a silly question i should probly make a new topic but what the hell.

What exactly is the purpose of an ignition and ignition box. i'm not even sure what the part is that im asking about but people ask me what type of ignition i have, and i say the kind that you put a key into and turn to start the car. Is there something i'm missing, is it performance related, if so is it worth losing the stock one. Help! im a newbie.

when they ask about your ignition they are problaby talking about of two things.

1: the actual distributor. is it stock HEI, Accell, MSD, or whatever.

2: an ignition box (also heard them refered to as spark boxes) you dont have a stock one, so they are asking if and what you run as an aftermarket box.

stock HEI isnt a bad system, so you dont need to lose it, but it could use some improvement. I had great luck with my MSD 6A ignition box, and standard coil adapter. the box definetly made starting easier, and smoothed out the idle big time. though I reccomend the 6AL insted of the 6A, because the 6AL has a built in rev limiter.

you can also jsut upgrade to a performance HEI coil and get a box.

Well, to me, about the only thing that an upgrade to the ignition system will do, is MAYBE increase fuel mileage, if your ignition is lacking a certain something, because it will 'supposedly' help the mixture in the combustion chamber burn better and fuller. *shrugs*
The only other thing I can think that it would be good for, is if you're running extremely high compression. It'll give you a much hotter, harder spark, which is needed for higher compression engines.

Other than those two things, to me, there's no point in upgrading, unless you want to be able to retard your ignition quickly by turning a dial on the front of the box. :P


As for the intake not being able to fit under the stock hood, if says anything about 'high-rise' in the product description, there's no chance in hell that it will fit. Otherwise, I *THINK* it will. I wouldn't chance it though, whoever you wind up buying the intake from, ask them if it will fit under a stock '79 Z28 hood. If you're buying it from a friend, or club member, chances are they wouldn't know, but if it's from some place like Jegg's, or Napa, or something, they should.

Just my opinions, of course. :D