When i bought my car i was told it was a 350, it came with a 305 from the factory with a 5 speed tranny (87 GTA). I wanted proof of this so i went looking on the block, which was real hard. Anyway the numbers i found don't appear to be casting numbers. Heres what i found: GM 57LG(or 6) then under the 57LG(or 6) was SGI then i found a 0020 no where near the numbers i just mentioned, the numbers were not stamped in but puffed out i guess you could say. They weren't indented, they came out of the block. So anyone know what this is, i'm guessing since it says 57L this means 5.7 liter gas??

where exactly did you find those numbers .i searched onthe block of my 86 ta and couldn't find any numbers

on the drivers side, near the firewall, straight down then a tiny bit towards the middle of the car, this is the best way i could explain, sorry

Yea, thats a 5.7 alright. Those were by the tranny bellhousing, driver side I would imagine. Theres also a 3 digit code on each side of the block, they are the last 3 digits of the part number for the block.

I hate to burst your bubble, but my 305 also has the "57" on the left side of the case, as do most iron SBCs that used the outer mold pattern for cases under 400 cubes.

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Vader
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"I'm'a do Things My Way - It's My way or the Highway."
Adobe Acrobat Reader

the numbers you need to find are on the front of the block just above and slightly to the left of the timing cover in front of the pass side head.

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86 Camaro with 88 305 LB9 using 86 carb setup, edelbrock performer manifold, 305 S/R Torquer Heads, Hedman Headers, Crane Compucam 2032 edelbrock cat-back, gutted cat, slp underdrive pulley, mallory ignition, 305 h.o dual snorkel air cleaner, hypertech thermomaster chip,160 degree thermostat, 5-speed, 3.23 posi

95 Beretta Z26, 3100 V6, 4 Speed auto, stock

Ive never heard this before. The few 305's I actually looked at had 5.0 on the case, not 5.7

I called a few GM dealers and a few garages and they all told me that means it's a 350. One person said the L is a 350 code as well.

The L is not a 350 code.

The best number to get is a 6, 7 or 8 digit number, located somewhere very near the "5.7L" that you found. It might be something like 14088526. All numbers, no letters.

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"So many Mustangs, so little time..."
ICON Motorsports

madmax, i though i had a 350 once also, i pulled my 86 LG4 out and it said 57 on the back also the 88 roller 305 i put in said 57

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86 Camaro with 88 305 LB9 using 86 carb setup, edelbrock performer manifold, 305 S/R Torquer Heads, Hedman Headers, Crane Compucam 2032 edelbrock cat-back, gutted cat, slp underdrive pulley, mallory ignition, 305 h.o dual snorkel air cleaner, hypertech thermomaster chip,160 degree thermostat, 5-speed, 3.23 posi

95 Beretta Z26, 3100 V6, 4 Speed auto, stock

ok i went and looked for the numbers again, theres no other numbers back there, where else can i look?

The numbers are back there. They are in the same place on every block.

They are also inside the timing cover.

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"So many Mustangs, so little time..."
ICON Motorsports

what is the best way to find the numbers is it open your hood. or lift the car up

They're up on top, so you have to do it from above. Not exactly the easiest place to read numbers from, in defense of the other guy. It's tough to see down in there sometimes.

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"So many Mustangs, so little time..."
ICON Motorsports

I just posted a thread on this a little bit ago asking what my block was also. I think i may have answered my own question but i'm not too sure. Check this out. You need to get the numbers off the rest of the block first. But this should help.

http://www.nastyz28.com/sbchevy/sblock.html

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1987 IROC-Z L98,SuperRam,EB 6085's,LPE 219/219 Roller, Crane 1.6RR, EB TPI Base, 58mm TB, ADS 24#, AFPR, K&N, EB TES, Catco Cat, 3" Borla Cat-Back, Accel cap,rotor,distro/other crap, MSD 6AL, MSD Blaster 3, Aluminum DS, 94 Disk Rear, Adjustable Valve, Precision 3.73 Gears, Sub-Frame Connectors, Hotchkis Lower Control Arms, KYB Shocks/Struts, Suspension Techniques Lowering Springs, Polyurethan Bushings all over the place, Moog Upper/Lower Ball joints and Tie Rods ends/Idler Arm,

To see the ROC, Check out the webpage Here

ok me and the car are going round three tomorrow. I will not leave the garage until i find these numbers. If you say there the same on all blocks, where excactly are they. I looked straight down from the distributor and to the right and these are the only numbers i've found. Ant help before i try again will be much appreciated.

I'm not sure what year but either '87 or '88 GM started putting 350's in ALL GTA's and 305's in the regular TA's!! I think it was '88....but in '87 I'm sure the 350 was an option!!

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1986 Trans AM
305 TPI
200,000+ miles (speedo/odometer non-funtional! Odometer reads 142,000)
4 Wheel Discs
9 bolt Borg Warner Rear (2.77's....oh joy) :P
Completely Stock
Soon to upgrade to a 383 converted from TPI to Carb, Edelbrock 600CFM Carb, Edelbrock Performer RPM Intake, Hedman Shorty Headers, AFR 195's (if I can afford them), XE268 Cam, Moroso HEI ignition kit with external MSD Blaster II Coil and an MSD 6-AL Box!!
Current project: Keeping my 305 running until I get my income tax returns!

i know this is an old post, but i kept gettin screwed around with this 350 my buddy was supposed to pull outta his truck and give to me for $100. so weeks months went by, then my sisters boyfriend, had a 350 sittin in his dads garage for years, so i picked that up for $100 still spins was rebuilt, originally blue, but painted orange, pulled the numbers off the head and last 3 numbers were 416, but my block my numbers are along the lines of 14010202. i take it i got a 305? and whats the diff between the ones with the last number 201, 202, and 203 at the end?

so i was thinking, if he sold me somethin its not, and i have to wait to grab that 350 off buddy (72-77 350) but pull my 416s off and port? any areas that need to be done, and i noticed welds along the inside of the ports? ok to make flush? thanks