How to tell if i have a 350 or 305
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Car: 1992 Z28
Engine: 350 tpi
Transmission: 4L60
Axle/Gears: 3.23
How to tell if i have a 350 or 305
Is there any way i can tell the 2 apart besides taking it apart? I got this car used and i was told the 305 was replaced with a 350 but how can i be sure he is not lying?
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Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Re: How to tell if i have a 350 or 305
The RPO will only tell what was in it originally. Check the casting numbers on the block to find out what it is now.
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Car: 87 IROC L98
Engine: 588 Alcohol BBC
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Axle/Gears: Ford 9"/31 spline spool/4.86
Re: How to tell if i have a 350 or 305
Suffix number on the pad in front of the passenger side head or the casting number behind the driver side head. The suffix number is usually hard to read. If the block was ever decked, the suffix number will be gone.
Since the 305 and 350 use different bores, a casting number can easily tell if the block is for a 305 or 350.
Since the 305 and 350 use different bores, a casting number can easily tell if the block is for a 305 or 350.
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Car: 1992 Z28
Engine: 350 tpi
Transmission: 4L60
Axle/Gears: 3.23
Re: How to tell if i have a 350 or 305
all i can make out on the pad behind the drivers side head is the GM logo and 5G does that tell me anything? I was told that it was replaced with a 350ci gm goodwrench truck engine.
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Car: 91 RS
Engine: 350 vortec
Transmission: T-5
Axle/Gears: not the best not the worst
Re: How to tell if i have a 350 or 305
i would be willing to bet that the 5G you are seeing is really 5.0... the thing with casting numbers is that you really have to have them super clean and even then some digits can take some creative guessing... but on a relativly new engine it should be pretty clean back there so you should look for a string of numbers further outboard of the 5G you saw
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Car: 87 FIREBIRD / 89 TRANS AM GTA
Engine: Ls1 / 350 L98 TPI
Transmission: 4l60e / 700R4
Axle/Gears: 3.73 / 3.27
Re: How to tell if i have a 350 or 305
i would be willing to bet that the 5G you are seeing is really 5.0... the thing with casting numbers is that you really have to have them super clean and even then some digits can take some creative guessing... but on a relativly new engine it should be pretty clean back there so you should look for a string of numbers further outboard of the 5G you saw
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Car: 86 Corvette, 89 IROC, 1999 TA
Engine: 350, 350, LS1
Transmission: 700r4, 700r4, T-56
Axle/Gears: 3.07, 373, 4.10
Re: How to tell if i have a 350 or 305
Refer to this link for casting number location.. http://www.mortec.com/location.htm
#10
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Car: 1992 Z28
Engine: 350 tpi
Transmission: 4L60
Axle/Gears: 3.23
Re: How to tell if i have a 350 or 305
Ok its confirmed it IS a 5.7L. I found that out behind the drivers side head next to the big GM stamp it said 5.7L. The 5g i saw before was actually SGI. so what would the date be? I read the link that 89rspower gave me but there is no way i will be able to see them numbers. Im just looking for a general idea what year it could be. This engine does have centerbolt valve covers so its a newer block. Also, I was told that the computer and tbi unit was not replaced with 350 stuff how does this run using a 305 computer and throttle body? i know it really doesnt have the power it should but should it be running with a 305 computer and throttle body? Also what would i have to change? Could i just change the fuel injectors and prom in the computer or should i replace the whole throttle body and computer? One more thing is there anything else i should replace?
Last edited by berlincam86; 10-01-2007 at 08:41 PM.
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Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Re: How to tell if i have a 350 or 305
If it has the 5.7 cast on it, then it's a roller block.
#12
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Car: 1992 Z28
Engine: 350 tpi
Transmission: 4L60
Axle/Gears: 3.23
Re: How to tell if i have a 350 or 305
what year did they start making the 350 a roller block?
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Car: 1992 Z28
Engine: 350 tpi
Transmission: 4L60
Axle/Gears: 3.23
Re: How to tell if i have a 350 or 305
This is a GM truck replacement motor and i cant find one that has a roller cam.
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Car: 89 IROC
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Re: How to tell if i have a 350 or 305
Well you've found the casting numbers but just to make sure I'd try mashing the skinny petal on the right. If the car fishtails... it's a 350.
#22
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Car: 1992 Z28
Engine: 350 tpi
Transmission: 4L60
Axle/Gears: 3.23
Re: How to tell if i have a 350 or 305
its definetly not fast as it should be and im pretty sure its because of the 305 throttle body and computer. I still havent gotten an answer from that post.
#23
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Car: 91 RS
Engine: 350 vortec
Transmission: T-5
Axle/Gears: not the best not the worst
Re: How to tell if i have a 350 or 305
on second thought it is a carb... i thought those could pretty much adapt
#24
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Car: 1992 Z28
Engine: 350 tpi
Transmission: 4L60
Axle/Gears: 3.23
Re: How to tell if i have a 350 or 305
im just thinking the computer is not giving it enough gas as it should be for a 350.
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Car: 89 Firebird Formula **MODIFIED**
Engine: 330 HP Crate 350
Transmission: 700R4 with Shift Kit
Re: How to tell if i have a 350 or 305
Easy way to tell if you have a 305 or a 350 from that year.
Hit the gas...
I can attest to this because I actually did the motor swap. 350s really have more power, especailly above the 3000 RPM mark. Mine Dyno'd at 330 HP.
Hit the gas...
I can attest to this because I actually did the motor swap. 350s really have more power, especailly above the 3000 RPM mark. Mine Dyno'd at 330 HP.
#28
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Car: 1992 Z28
Engine: 350 tpi
Transmission: 4L60
Axle/Gears: 3.23
Re: How to tell if i have a 350 or 305
Ok guys thanks for your help but i actually sold the car that i was having problems with not because of the problem but because i wanted another car. Thanks alot for all the help i learned alot.
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