can I put 350 headers on my 305? The reason for this is that right now my 305 isn't quick unuf for me. Header's would help this. But later on I'm getting a 350, then I could just use the headers I have on it instead of buying 2 sets of headers. Can it be done?

 

Sure, i have the same deal with mine and it runs good.

Jeremy

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92 Z conv
5-spd B&M shifter
home-made ram air, air foil, headers, no cat, TB bypass, kevlar pads, slotted rotors, BMR panhard, alston SFC
when it warms up Edelbrock STB maybe springs

 

Yes, 305 and 350's use the same headers.

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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

Are you saying that a 305 can run with 1 3/4" headers from SLP? I would think that a prepped 305 would benefit from 1 5/8" headers, but 1 3/4" just seems way to big to me. Wouldn't you lose a huge amount of torque because of the big tubes on such a small displacement motor?

 

Yes, David, you wouldnt want to use 1 3/4" headers on a 305 for the reasons you described. But the headers are still interchangable on all small block chevy engines.

 

Along with the headers you should upgrade to a dual cat y pipe and a catback exhaust. Thats what I'm doing.

 

i think from your post, yo uwant to put the 350's manifolds on a 305?? if so, i hear its a PITA and they are the same things anyway (i believe).

-Stell


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1988 IROC 305TPI MINT!!
Mods= Accell SuperCoil, MSD 6A, Ported Plenum, No MAF Screans , K & N, 160 Thermostat+ Temp Switch, Relocated MAT, Cold Air

 

who cares about torque!!?? if your really getting a 350,get the 1 3/4"s!! I have(had) a 305 with 350 tpi headers on it,sure it might lose some torque but at least I have no trouble climbing steep hills,and gets better fuel economy too.

......350 tpi comming very soon.

 

Putting on headers on that 305 is Easy. I sold my buddy my Flowtech Junker headers off my old 350 and we had them on his 305 in no time.

 

unfortunatily I have the Edelbrock headers off of my 305 on the new 350. They fit perfectly but OH!! the restriction.

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1983 Camaro Z28
Goodwrench 350ci V8, Edelbrock TES Headers, Flowmaster Catback, MSD 6al and Blaster 2 coil, Edelbrock Performer intake, Edelbrock Performer 600cfm carb. T5, 373 rear, Eibach springs, Cervin Vega speakers, Rock. Fos. Sub, Pioneer CD,
email-chris4421@hotmail.com
-------------------------
"I used to be a Mustang Guy! I didn't know the power of the dark side!!"

 

So which ones should I get?

 

If you plan on getting a 350, then get the 1 3/4" headers. There are ways to regain the torque loss that I plan to experiment with until its time for an engine swap.

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92 Camaro RS LO3, 5-spd, T-tops
Performance:
SLP 1 3/4" Headers (Coated by Paul Barry Motorsports), Flowmaster Catback Exhaust, Fastchip Performance PROM, Centerforce Dual Friction Clutch, Xact 8mm wires, Open Air Element w/K&N Filter, Z28 Grille w/aftmkt fog lamps
Electronics:
Alpine 8030 Alarm System, Valentine One Radar Detector (How did I ever drive without one?), Pioneer DEH 7450 Head Unit w/6-pack CD changer, Pioneer DEQ 7600 Sound Processor, 2 Kenwood KAC-846 Amps powering 2 12" Pro Red subs, 2 Pioneer 6x9 and 2 MTX 4x6 speakers.
NEXT UP: TBI mods, Edelbrock performer intake

 

I think a lot of the responses overlook a very important principle: using a balanced approach to choosing parts/modifications to improve performance. Sure you can slap a set of 1 3/4" headers on a 305, but they won't improve the engines breathing ability(versus 1 5/8" headers) until the engine speed exceeds 6000 rpm. But in the meantime, the larger headers will have a reduced scavenging ability through the engine's low and mid range operation. This will hurt fuel economy(less efficient combustion) and all-around performance(decreased cylinder-filling efficiency). And adding the larger headers alone would still not allow your 305 to make worthwhile power at or above 6000 rpm, unless all the related sytems(induction, valvetrain, ignition, etc.,) were likewise designed to produce power at such high engine speeds.

Adding the large headers would in essence hurt performance at any engine speed with no real benefit. And as far as I am concerned, anyone who says: "Who needs torque?", is someone who doesn't have a clue. Torque, not horsepower, is what moves your car, lets it climb steep hills and makes driving worthwhile.

From a fitment point of view, yes you can slap any set of "350" headers on a 305. The question is: why would you?

Btw, I have measured(bore guage and dial calipers) the factory manifolds from both an LB9(305 TPI) and an L98(350 TPI), and there is a difference. The LB9 manifolds have 1 3/8" ID, and the L98 manifolds 1 1/2" ID. You might see a small gain from using L98 manifolds on a 305, but I wouldn't bother unless you got them real cheap(read: free).

Btw#2, if you are really serious about making serious power from a 305, you might want to investigate what is involved in building a SCCA "A" Sedan engine. This class is restricted to thirdgen f-bodies and fox-bodied(1978 - '93) Mustangs. The rules state that engines are limited to balanced and blueprinted production-based carbureted engines displacing no more than 5 liters(305 cid). If the accounts are accurate, the fastest cars in this class are making nearly 600 hp. Food for thought.

 

I care about torque...
Websters...
A force that produces or tends to produce rotation or torsion (an automobile engine delivers ~ to the drive shaft) also.. a measure of the EFFECTIVENESS of such a force...
My ship, a 567 ft/9900 Ton Aegis Cruiser, has 4 LM2500 Gas Turbine engines producing a total of 80,000 shaft horsepower. Without a reduction gear to take the high RPM, low torque output of the Gas Turbines, and converting it to low RPM, high torque, the ship would not move. HP numbers are great, but TORQUE gets your car moving.



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Rob P
89RSconvtZZ4TPI
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

 

ok, i have stock 305 manifolds on my 350. is that bad?? i'll eventually get headers but for now??

 

Stock manifolds are always bad, compared to headers.

 

I'd get the 350 headers if you're not going to use the 305 much longer. Or if you are difinetely planning on a 350.

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1989 Pontiac Firebird
Formula W6S LO3 TBI 305
-180 degree stat
-Hooker Cat-Back




1985 Camaro IROC-Z LB9

http://www.geocities.com/krt80/


[This message has been edited by Keith5 (edited January 07, 2001).]