In my 1990 Iroc, I have a 305 5spd TPI with G92 performance package (hotter factory cam; the L98 cam). I want to put in a 350 real soon. Besides the injectors, what will I need to replace? Do I need a whole new ECM, or just a chip change? I have an adjustable fuel pressure regulator so the extra psi, won't be a problem. Any info will be greatly appreciated!

 

Besides the injectors, all you should need to change is the chip, the ecm itself is the same. All stock 350 chips are for automatics, but this shouldn't present any problem with a five speed. I've heard the only thing it affects is your shift light won't work anymore. Shift lights are stupid in my opinion anyways. I've also heard of people running the 305 chip with a 350 without any major problems, they just say that you will optimize your power by changing to a different chip. If you want to spend the money, you could always have a custom chip made for your car.

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89RS w/350 TPI; 69RS/SS w/450 HP 350/Muncie 4-Speed "Too weird to live, too rare to die."

 

Here's the thing with my Ed Wright (Fastchip.com) stage 2 chip, on the chip itself it says it's for a 350 because of the cam I would guess. I remember asking him about the chip, I didn't want to get a chip for a 305 that redlines at 4500, I wanted to be sure to get the chip for the 5000 RPM redline. So, I believe it may work at least temporarily. Now all I got to do is locate a block or partially built 350!

 

The PROM, the injectors, and the knock sensor are different. I used the stock 305 5-speed chip in mine with no trouble. I've also used the stock 350 chip but I didnt notice a difference, except the lack of the shift light, like was said above.

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West Coast GM Shootout 2001!
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=-

 

Remember kids, in Speed Density LB9s, there is but one cam, the L98 cam. I feel like I'm on a ****ing jihad here.



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91 Trans Am WS6
Bright White
5.0 TPI auto
Flowmaster 3" 2 chamber catback
Trans Go shiftkit
2000 stall converter

Built on Wednesday

 

Alrighty then, chill out, I'm sorry I didn't know that ALL the LB9's came with the L98 cam. I thought that there were two cam choices for the 305. SORRY!