Considering rebuilding 1979 l48. All stock, 3.55 rear, th350. Factory wheel/tires. I cant nail down what numbers i want as far as hp/tq, i do want-need the car to break the wheels free from a dead stop, and also be able to squeal while cruising at say 25mph, and gun it.

I don't want to have to make huge mods to the cars appearance, ie hood swap, etc, maintain factory look, and still use all vacuum req'd equip. It just feels lazy when I drive it.

My daily driver is a '11 duramax, and I absolutely need my car to be able to out run it!



I'd like to stay under 5k, which should be easy.

I've been checking out summit and edelbrock packages, are these real options,

I'm loving all I read about AFR heads, are they really what I need, or just what I want?

Also, I'm not considering xo to vortec setup.

Would like to go with roller rockers.

Thanks for advise in advance.

 

Flat tappet cam?

An AFR 180 head, Isky 270 mega cam 1-5/8 headers...good dual plane should get you what you want meet your budget. Good curve on the distributor...maybe have lars touch your Qjet (Im assuming). Adding a 2500 maybe a 2800 stall would make it real fun keep your same rear gear

http://www.airflowresearch.com/chevy_dyno.php

Youll make 10-20 more with the Isky than the Comp.
Fun street motor

 

Just added that like to my faves. If I up sized that carb to 750 dp, would I see gains in hp/tq? Would I lose vac?

Not to concerned on fuel mileage either, since ill only ever get about 5000 miles a year on it anyway.

The reason I'm curious about the carb is because when I was into building engine, ( before all the Internet tech) when all u had was your buddies in someone's shop, we all had to have the 750 dp?

 

thats what i thought holley dp was the way to go BUT for a street car under 500 hp the Qjet will work killer i got ahold of CLIFFS performance Qjet carbs and talked to him about my carb and read his book on them and man when that 4bbl kicks in it just screams and roasts the tires talk to cliff or Lars about your Qjet im glad i did and i get 14.25 mpg when i had dp 8 to 10 mpg

 

In this application, what is that should be governing my cam choice, as far as valve open, close, duration, lift, and lobe separation, I've read lots on this subject, but I can't see the "why" I should pick "this"cam.

 

Not an auto man but maybe you should start considering a higher stall converter well matched to the maximum rpm torque of whatever cam rpm range you end up with. Always seemed to me that with an auto car that should be very high up on ones list of improvements.

You can do better then looking at edelbrock packages for the engine. Theres better heads for under $1.000.00 then what edelbrock sells.

As far as heads if you only need or want so much power as your goal do you need the most expensive heads ? Think about it.

If you have a stock exhaust system it should be first on your list to get rid of there super restrictive on a 79.

 

like that combo ,AFR with a dual plane intake.consider a elderbrock performer and a comp ex268h cam,it will make great toque and good hp.get a 750 DP not a 750 vacuum secondary if you want more power.look at a quick fuel carb .get a distributor that has adjustable vacuum ,like a MSD HEI.

 

Higher stall is on the list, car also has headers and true dual exhaust. I'm trying to stay away from a target numer for hp, I just really want it to pull hard, but not to extreme.
By that I mean, I want to be planted I'm my seat, but don't want to do wheelies

 

I gotta say, that 750 dp, is something that's been burned in my mind for 15+ years now, it's what I had on a 400cid I had, would it be too much on a 350?
Defiantly gonna get a new distributor, that was something I skipped on my 400 and always regretted it.

 

Well sorted out Q jets are great best of both worlds.


If you go holley get a 650 DP thats all you need. The HP series are super nice. 750 wont hurt ya at all but youll love how snappy and responsive the 650 is with that combo .


Make sure you have a good curve on that distributor that makes ALL the difference in the world. It can turn a dog or flat poweband into something that makes ya grin.

 

This is what I have on my 355, AFR 195 and cc280H. Great combo but I'm going to a HR with .560 lift soon.

 

Have you considered a ZZ4 crate ? Would make life real easy 355 hp 405 tq and very very nice to drive on the street

 

I have always had the old 4779 series holley double pumper 750 or vacuum 750s. But the truth is they are stuck in the 1960s tech with very little adjustability.

If i wanted a new double pumper today for a street carb i would use a carb like this quick fuel part number QFT-SS-750-AN. It has (annular boosters) electric choke, four corner idle system, you can change they idle feed, power valve channel restriction, change idle and high speed air bleeds.

The roughly $350.00 4779 you get none of this tunability much less annular boosters like i said its a stuck in the 1960s carb. It has zero of these adjustments i just mentioned in the quick fuel carb.

For gods sake lol with your $4000.00 budget buy yourself a carb for another roughly $200.00

Now quick fuel does make a 650 version but i would do the 750. Annular booster are a little bigger in the air streem but would creat a strong throttle response. If you were drag racing keeping your engine at constant high rpms then you would want a dog leg booster.

Demon has also just came out with new street carbs with annular boosters.

Don't let people jack you up with the smallest carb on a dual plane manifold. Your going to be going after more airflow into the engine with better heads and camshaft. I also would not do a performer manifold use one of the rpms don't creat an air restricton with the manifold.

 

That setup, plants you in your seat?. I really like the idea of proven recipe.

 

Not really, wanna keep the original power train, just beef it up

 

The q-jet is gone, it's got a carter carb right now.

 

Have to write a book for that one. Go with a cam around the 270 range intake duration as much lift as possible and if your exhaust is real free flowing go with a single pattern cam. If not the lunati voodoo 268 would be my choice. Before you buy it check your DCR to make sure your not to high. If so you will have to go bigger on the cam and convertor. 112 LSA with an automatic,. 110 is ok if it isn't available. If you want a radical idle and the race car sound go with the smallest thumper cam but you will give up noticable power.

 

So many time I think I know what I want, start researching, then I usually confuse my self and give up.
Definitely would not want to sacrifice power of idle sound.

But this is what I've been looking for, good input on options. 270 range is what I think I'd like, lobe seperation is something I've struggled with. And I will now keep the # in mind. Thanks!

 

Almost ready to fire up the motor with the new roller cam..My write up..
http://forums.corvetteforum.com/c3-t...-cam-swap.html
Just looking at the difference in cam profiles,you can tell the roller is gonna make power..
[IMG][/IMG]

 

[QUOTE=iokepakai;1582977753] Just looking at the difference in cam profiles,you can tell the roller is gonna make power..

Yes. The difference in the cam ad where it shows Advertized duration and duration @ .050 is a minimal difference but the difference in duration @ .200 and duration @ .400 is huge! That is where flow is higher and power is made.