I'm pretty pissed off.. I think I'm gonna get headers in 8 hours to make me feel better. whats the difference between the TBI headers and TPI? I know the cat conncetion is 2.25" vs. 3" but what else is different? is the Y pipe diameter coming from the headers different? is the point where the 2 pipes merge different? thanks

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-Tas
'89 Formula WS-6
[soon to be Performace Red =) ]

305, TBI, auto, 14x3 chrome flat based open element with K&N, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips....

Super GRK_Taz World
EFI & Intake Options
AOL IM: superGRtaz
ICQ 82881207

 

If you're comparing the 6875 TBI headers to the 6872 TPI headers then there are a few differences. First is the collector and Y pipe diameter which is 2.5" on the TPI headers while it's 2.25" for the TBI. The pipe to the cat is 3" for TPI compared to 2.25" for TBI.
Unless you absolutely have to use the TBI headers,go with the TPI set. I've used both and the difference between the two is impressive.


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Mongoose-NCTGA-1990 Pontiac Formula/305 TBI-700R4 with Edelbrock Performer TBI intake,TES headers,and STB,K&N,MSD-6AL,Holley laser shot coil,Accel Extreme 9000 wires,Jet Stage 2 chip,TCI shift kit with corvette servo,Richmond 3.73 gear with Auburn 3 series posi,no cat,SLP 3" cat back,Eibach sportline springs,Energy Suspension poly throughout,Lakewood LCA and adjustable panhard bar package,SSM subframe connectors,IROC wonder bar,Tokico 5 way adjustable struts and shocks,Autometer electric fuel pressure gauge,Alpine,JL Audio,MB Quart,92 GTA taillights,92 GTA aero wing and hatch,Steve Spohn LCA relocater kit,MacEwen White face gauges,84 T/A cold air induction air cleaner,Grant Formula GT wheel.

 

I use the TPI headers on mine. they are far better than the tbi junk

 

thanks guys. but now I have to get a cat

 

I've been told that the TPI headers are too big for the L03, and that a lot of torque is lost...what's the deal?

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'89 RS LO3- 140,000 miles
14x3 K&N Open Element
Ram Heavy Duty clutch (yes, I think it's great)
Dual .50 caliber machine guns just under ground effects

Coming very soon:
Edelbrock TES (Jet-hot coated)
Catco cat
Edelbrock 3" Cat-back
KYB shocks
Edelbrock Strut Tower Brace
South Side Machine subframe connectors

When your buddy reaches for a 10-pound sledge and says "I think we're gonna have to modify the floor pan, okay?" the answer is NO.

 

TPI headers aren't too big at all, backpressure is hardly an issue with a 305..

 

Don't forget that you have to deal with the smog police. The TPI headers don't have the heat stove on the drivers side.

 

ya I thought about the heat riser. I'd take it off the stock manifolds or make a new one.

 

What exactly is the heat stove? I'll need to pass sniffer in MA eventually, and they're crazy about smog laws...can I fabricate one? I can barely tie my shoes...is this possible? Will I get a constant "check engine" light? Sorry I'm clueless, but I'm about to buy some TES headers, and I really want to know everything I can before I commit...

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'89 RS LO3- 140,000 miles
14x3 K&N Open Element
Ram Heavy Duty clutch (yes, I think it's great)
Dual .50 caliber machine guns just under ground effects

Coming very soon:
Edelbrock TES (Jet-hot coated)
Catco cat
Edelbrock 3" Cat-back
KYB shocks
Edelbrock Strut Tower Brace
South Side Machine subframe connectors

When your buddy reaches for a 10-pound sledge and says "I think we're gonna have to modify the floor pan, okay?" the answer is NO.

 

Go out to your car and look at the drivers side manifold... you will notice a 1" or so diamater tube going from it to the air cleaner. This heats the air when the engine is cold and aids fuel atomization, drivability and engine warm up when the car is cold.