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swapping out 305 for 350

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Old Jan 9, 2007 | 07:20 AM
  #1  
Iroc_man's Avatar
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From: Shangri-La
Car: 87 Iroc
Engine: 305 TPI
Transmission: 700R4
Axle/Gears: stock posi
swapping out 305 for 350

hey, i am going to put an 85-86 350 in my camaro, im going to swap the TPI stuff from the 305 (1987) onto it. what all do i need for the swap? anything else? new computer? or is that all?


also, if i used my 305 heads on the 350, could i still use pump gas? how much compression am i looking at?

Last edited by Iroc_man; Jan 9, 2007 at 07:23 AM.
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Old Jan 9, 2007 | 01:06 PM
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
'85-'86 engines had all 90 degree intake mount bolts. The center two bolts of your '87 are 72 degree. Not a real big deal, but you'll need to either get an earlier (or Vette) base, or modify those mount bolt holes (elongate them).

You don't necessarily need to change anything to get it to run, but it will probably run better with 22 lb injectors and a 350 PROM. You should also get a 350 knock sensor and module.

The resulting compression from putting 305 heads on a 350 shortblock depends upon the pistons in the 350. If they're dished (and they likely are, especially if the engine came out of a truck), then you won't have any problems. If flat tops or slight dish with valve reliefs, then you'll likely be a little high for regular, but may be okay with premium.
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Old Jan 9, 2007 | 08:42 PM
  #3  
Iroc_man's Avatar
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From: Shangri-La
Car: 87 Iroc
Engine: 305 TPI
Transmission: 700R4
Axle/Gears: stock posi
can i just use the holley stealth ram intake from summit? and then would i need anything else?

http://store.summitracing.com/partde...5&autoview=sku

Last edited by Iroc_man; Jan 9, 2007 at 08:50 PM.
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Old Jan 9, 2007 | 10:23 PM
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five7kid's Avatar
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
With what heads?

Still need injectors and throttle body. And most likely a PROM that can take advantage of the intake.
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Old Jan 10, 2007 | 05:28 PM
  #5  
Iroc_man's Avatar
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From: Shangri-La
Car: 87 Iroc
Engine: 305 TPI
Transmission: 700R4
Axle/Gears: stock posi
their probably the stock 1985 350 heads
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Old Jan 10, 2007 | 11:56 PM
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five7kid's Avatar
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
What was this 350 engine in originally?
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Old Jan 11, 2007 | 07:31 AM
  #7  
Iroc_man's Avatar
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From: Shangri-La
Car: 87 Iroc
Engine: 305 TPI
Transmission: 700R4
Axle/Gears: stock posi
a truck
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Old Jan 11, 2007 | 08:44 AM
  #8  
five7kid's Avatar
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Very poor heads. Your 305 heads would be tons better.

The dished pistons that the truck 350 most likely has will keep compression reasonable with the smaller chambers of the 305 heads.

Put your 305 heads on it. If they were machined for 1.94" intake valves, with mild bowl clean-up (porting) and have new springs put on, they will be even better.

Last edited by five7kid; Jan 11, 2007 at 02:45 PM.
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