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Help with 71' mods.

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Blue71'Conv

Guest
I am trying to find out if anyone make headers to fit a 71' 350. I can't seem to find any online.

I am also looking to get a few more 'ponies' out of the currently stock engine. Any ideas (that won't cost me as much as the car), would be greatly appreciated.

Thanks.
 
S

sscam69

Guest
I just bought some headers from a local speed shop for about $100.

You might try summitracing.com they have some headers you can purchase at a good price, about 90$

You can also change the manifold to a edelbrock performer as well.

The rochester is a really good carb to have on that vehicle, better than Holley in some aspects, but it does not have a good reputation due to its complexity (thats what makes it good, it is a really fllexible carb).

Or you can go N.O.S for the extreme but i don't think the engine is built to handle it, your bound to blow something if you go that route.
 
J

Joeverb

Guest
I think the holleys are more popular than the quad cause they are cheap, easy to adjust,easy to rebuild and various performance kits are available for them at reasonable prices. Thus i use a holley..LOL, i never was any good at adjusting the quad.




On a side note.....Why does everyone have issues with N2O? Granted you dont want to put it on a high mileage engine unless you know its in good shape but a 100 to 125 hp plate system is a slap on the wrist to a 350 chevy.
 

Ganey

Well-known member
Joined
Jan 7, 2001
Messages
94
Location
Texas
Corvette
385 CI 77 CORVETTE FE-7 Hi-Perf Sus.
Get Dynomax coated headers fit & flow great, about $200. Available from Summit or Jeg's. Performer intake is fine. Edel. Performer cam is not enough for a CORVETTE !

Needed for cam, What is your engine, trans. & gears?
 
7

72 Bluz

Guest
Good advice

This is helpful to me as well. What are some good plug wires? I noticed that the plug connectors were starting to look weak and show some cracks. Also looking at a manifold and ignition upgrade. Still haven't decided on what stickers to use. :confused

Also, Blue 71, consider a heat shield for your starter. Won't help add hwp, but may save you from some of the problems I have had, especially if you add headers.

72 Bluz
 

Ganey

Well-known member
Joined
Jan 7, 2001
Messages
94
Location
Texas
Corvette
385 CI 77 CORVETTE FE-7 Hi-Perf Sus.
Moroso or other spiral core wires.

Stickers? Stickers & emblems not rec. !
 
7

72 Bluz

Guest
What, no stickers?

Just kidding on the stickers, Ganey. :D

72 Bluz
 
S

sscam69

Guest
mods

My car is almost out of the shop. I mentioned before that my car will be putting out about 400 hp or so. I bought a rebuilt quad for 217 at the local checkers. The mechanic put it on and said that it responded better than the holley. Keep in mind that the smallest quad flows (technically) 750 cfm. In my opinion they are great carbs but you have to find someone that really understands them and knows how to tune them for your specific vehicle.

p.s. I am fortunate i found a mechanic that builds competition cars, i am getting more bang for my $ than i should. The guy was getting a kick of putting the engine together!

p.s.s. NOS can be destructive if your engine is not built for it.
 
B

Bullitt

Guest
NOS, squeeze, juice...

Joeverb is right. I think there is too much bad information on adding nitrous oxide. Of course, you don't want to put it on an engine that is near the end of it's life. But it would make a wonderful explosion if you wanted to really go out in style!:r First, do a compression test to make sure your cylinders are within 10% of each other. Nothing like uneven cylinder pressures to ruin your day. The problems experienced with some nitrous systems is that the builder does not upgrade their present fuel pump. More than likely, you want to use an electric pump with a fuel regulator. It is vital to make certain that your engine is getting enough regular fuel to mix with the nitrous oxide. Most cars came with fuel lines that are undersized, also. Corvettes usually don't suffer this problem. I don't suggest going for some 200hp shot. Keep it around 100-125hp. Try to refrain from using it in first gear. Remember, unless you are seriously racing, you won't use the "bottle" too often.--Bullitt
 
J

Joeverb

Guest
SS69 i can understand your thoughts on N2O but bullitt is right if the fuel pressure is there it is next to impossible to screw up with a small 100 to 125 hp system. I have loved the stuff ever since i took a ride in a friends iroc z that had it.

I have run it on several cars from 4 cyl to big blocks.And yes i have blown a few up but only on the bigger shots 225 hp cheater systems. Never not even once on the 100 or 125 hp shot. In fact on my mustang i had the worse possible situation happen on a run where the fuel solonoid for the n2o system died and i was shooting in just n2o. It was a 125 hp system at the time. It blew out the head gaskets and that was it. New head gaskets and back at the track for test and tune the next weekend. From this i learned to simply check the solonoid before a run and i never had another prob.

On another note with a cheater system 225 hp i actually bent the edge of a forged piston.But ive never had any probs with the baby systems 100 to 125 hp and thats still alot of boost!

All i got to say is dont knock it til you try it :)))))))))))
oh and i'll also say this damnnn what a rush
 
S

sscam69

Guest
LOL...... thats why i love racing, the adrenaline. Ok Ok Ok you convinced me. There is nothing like experience and it sounds like you have it when it comes to the small cheater. I actually want to add the NOS and bring my car up to 500 hp. That would definitly make the stangs think twice.

I will definitely use it as a future upgrade!

thanx
 
B

Blue71'Conv

Guest
Thanks.. but what else can I do....

I know what adding 'high flow' exaust and Headers can do along with a better intake, but TYLA, what was that about the ignition? I have heard about this before, but I don't remember the details.
 
B

Blue71'Conv

Guest
what about the tranny?

I have a 4sp tranny. Has anyone tried changing the gearing for 3rd and 4th. I'm looking to get highway speeds (75-85) without keeping the RPMs over 3k.

Any guess as to the cost, or potential problems?
 
S

sscam69

Guest
Differential

The best way to change the overall gear ratios is to change the gear in the differential. Its probably cheaper in this case as well.
It will affect your e.t.'s as well, negatively. But you will have better gas milage due to lower rpm's.
 
J

Joeverb

Guest
SS is right you start playing with the trans you are gonna want a trans like the richmond with many gear options, not cheap in the slightest but the ultimate in having your cake and eating it too.
 
R

redmist

Guest
Personally I would still rather have the gearvendor O/D then the Richmond 6 speed. The m-21s are bullit-proof. The gearing, with the exception of a lack of OD, is fine. No frame/crossmember alterations, lighter weight, shifting without a clutch and can be easily removed (NCRS folks will like this) and reinstalled in your next muscle car, auto or manual.
 
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Blue71'Conv

Guest
So far, so good....

OK, here's what I am looking at...

Hooker Headers
Flowmaster Exhaust
Edelbrock Performer RPM Intake and Cam
New Timing Gears (remove the chain)
New Valve Springs
K&N Filter System

But there's two more things that I need a little help with.

1. Which Ignition System is the BEST?
MSD or Mallory

2. The steering is almost too responsive. How can I get more 'feel' behind the wheel, and not cross both white lines when I sneeze?
 

Ganey

Well-known member
Joined
Jan 7, 2001
Messages
94
Location
Texas
Corvette
385 CI 77 CORVETTE FE-7 Hi-Perf Sus.
Blue71'Conv

You really need serious gears in the 4s for that cam & you need to rebuild, balance & blueprint. If you are saying gear drive instead of roller timing set, not the way to go for street.
 
B

Blue71'Conv

Guest
Back to the NOS...

Ok...

I've done some additional research on the NOS. If i'm not mistaken, Joverb.. I can add 150 Hp for around $400, and not blow my plugs out of the fender wells?

Would I still need to change my intake and/or anything else to make this work? She is a 71' original with 85K miles. Should I go ahead and have a standard re-build done, just in case something is loose or worn out in there?

If this will work, it sounds like it will be a blast! (pun intentional)
 
J

Joeverb

Guest
As long as the engine is in decent shape 150hp n2o shouldnt pose a prob. No you dont have to change the intake or anything with the n20 but keep in mind it will use a 1/2 inch spacer plate under the carb to inject it. I actually put a 125 hp system on a friends nova with a dieing smoking 350 4 V with headers. We figured we would send the old turd out in style. We whooped a few mustang gts choking them in the oil smoke but the engine continued on with no n2o induced trauma.

Actually the less efficient the engine the more power you will get from a given "shot" of n2o. For example 150 hp increase advertised will be based on a factory or near factory motor. The more mods you make to increase efficiency lessens the boost seen from the nitrous. add a good set of heads and cam that boost from the same shot of n2o may only result in a 120 hp increase. A gross generalization but you get the point.
 

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