Scott_92RS

Is there an yway I can tell if a car has a 305 or a 350 just by looking at it? Specifically in a 91 Z28? I may be buying a car, and the guy told me that car has a 350, but carfax tells me otherwise (305), and so does the VIN Decoder on this site. Thanks.

SUPER-SPORT-CHEVY

The small harmonic ballencer would be the first thing to look for on a 305 a 350 has a larger one. Sorry I cant remember the exact sizes off hand. The engine size is also stamped on the back ear of the block where the bell housing bolts the the engine driver side. 5.7 for 350 5.0 for 305. There should also be a sticker under the hood that states the engine size from the factory 5.7 or 5.0. It could be a 350 if it was replaced but if carfacts is telling you 305 its most likely a 305. Ask the guy if he replaced the engine. A dealer told me that my firebird had a 350 even though I knew it was a 305. A different dealer also told my friend the same thing about his trans am. You think you could trust a dealer let alone a private party.
SSC

Scott_92RS

Thanks man, anyone know the size of a 350 ballancer?

MRZ28HO

There are only two sizes for dampers, either 6-3/4" or 8" (but these were used on musclecar high performers). There is speculation that the damper is different, by means of it being thinner, but that is inconclusive. Best bet is to run the casting number from the block at either NastyZ28.com (best site IMO) or Mortec.com (alright IMO). Most blocks do not give the displacement (in liters or CI), so that could be out (see sample below). Also, do not trust what is stamped, labeled, or written on the car for the size of the engine. Why? Ever hear of engine swaps. Here is a link to what the casting number should look like.

http://mrz28ho.cz28.com/images/sbc-05.jpg



Sorry about image quality.

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George P. Lara
3rd Gen, 4th Gen
SCCA, SCFB, SC3GFB

[This message has been edited by MRZ28HO (edited May 21, 2001).]

Blue5.71LE

The quickest way just by looking, is the brakes, all 91 350's came with 4 wheel discs.

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91'1LE Z28
K&N Filter (just getting started)All show no go.For now.

Black Beauty

weve established that the car was originally a 305

he wants to know if its a 350 NOW. Drive it.
If its fast its a 350, if not its a 305

remove the head, check the bore and stroke

but seriously, check the casting number

Guest

You could get rear discs on a 305 car too, so that doesnt help.

Like George said, the only way is to get numbers off the block. You would never know otherwise.

Scott_92RS

I guess the easiest way for me to tell what it is will be to drive it. I know what the 305 TPI feels like, so I'm sure the difference will be pretty evident. I'll let ya know what I find out. Thanks guys!

TomP

Trick him. Ask him if that's the original motor.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

Scott_92RS

I plan on it Maybe I'll get him to cut the price even more cause I know the car has been seriously messed with. I'll buy it on the spot if he goes lower than 2500. That would be a sweet deal. A clean T-Top Z with a few problems for $2300-2500.

Bort62

If you think You can Tell a 305 from a 350 by driving it, Your deluding yourself.

There are so many variables, That it is impossible to tell the Two apart.

350's can range from a stock 150 hp, to stock 375(altho those late 60's eary 70's numbers are questionable), 305's from 150 stock to 200+, And who say's anything is stock.

Feel is absolutely useless in determining displacement.


The only Real way to tell is to check the casting numbers, or measure the bore. Mesureing stroke Wont Do you Any Good, because It is the same between 350's and 305's. Plus, To measure stroke, You would have to have The Motor all apart, and Then you could just as easily measure bore

Some 305's had a wider, Hollow Blancer, while Some 350's have a Narrow, Heavier solid One, But this is Only a Clue, I have seen plenty of 305's with 350 balancers, and Vice Versa.

the 5.7 Or 5.0 Stamping is Not incredibly valid, either. I have seen a few 305's with the 5.7 stamping Myself, I think Vader's Car is one example.

If the guy Tells you its a 350, but Dosent have extensive detail to backup the swap, Its probrably Not. When You swap a Motor In your car, specially a Fuelie, Its not something you just do without really thinking about it, Or remember details.




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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver 15.26 @ 87.0
Reader's ride -> My Ride

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

Scott_92RS

I'll find out one way or another if it is in fact a 350. I'll let you guys know what it turn out to be.

dhirocz

iTrader: (2)

OK, let's try this...on the front of an engine block, there are 2 water pump bosses, where the pump bolts to the block. On the passenger side boss, at the top, there are casting numbers. The numbers at the back of the block are part numbers, though some years say 5.0L or 5.7L back there. There are 2 rows of numbers, the last 8 or so of the vin number is at the bottom. Clean this boss with brake cleaner and a towel nd write these down. If the bottom row match the last numbers of the VIN, it's the original engine and since we know it came with a 305, no more work is necessary. The bottom row is specific to the engine VIN, no other block has this number inside that year. The top row are numbers that the dealer can look up and decode. The last three at the top row are most important. This way you'll know for sure.

Fred85TA

Is this just for Camaros? The reason I ask is because my 91 350 has aluminum drums. I also heard they had trouble with disk rears in 91 and didn't put them on our cars. Can anyone confirm any of this?


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91 TA 5.7 TPI Automatic.
Motor Mods: K&N, Hypertech Coil, Moroso Blue Max Wires, Bosch Platinum plugs, JET fan switch, JET air foil.
Exhaust: Dual cats with Flowmaster 3" exhaust (Headers coming soon)
Suspension: Complete PST on the front, Spohn LCAs and panhard bar on the rear.
It's not much, but it's a start and I have Summit and JEGS catalogs! :-)

Scott_92RS

I didnt even bother checking out the engine. The car needed quite a bit of work. None of the gauges worked, turn signals didnt work. Needed a new coil, plug wires, AC system, a few interior parts, hood and hatch didnt close right, front ground effects were cracked in a few places. It was not a very good car. Thanks for your help, though.