Is it a 305 or a 350?
 

Just out of curiousity, is there anyway I can tell if my TPI motor is a 305 or 350 without getting behind the block to get the casting on the back? Reason I'm asking is the other day a few of us got to looking at my motor, and the harmonic balancer looks like one for a 350 and not a 305. The motor has 170000 miles on it and runs damn strong for a 305, which is why i'm wondering if its a 350. The emissions sticker on the hood says 5.7V8, and appears to have been replaced, because the sticker is not in the same place as original, its a little off. However, my VIN says F on the 8th digit. I'm thinking(and hoping actually) that someone has replaced it with a L98. Any input would be appreciated. Also, what about the injectors, externally is there a difference between the 19's and 22's? Are they a different color by chance?

Pull off a valve cover and get the head casting number. Heres a head casting number list, just match em up.

http://www.mortec.com/castnum.htm

If the VIN says F then it was originally a 305 car, period.

Therefore, you cannot even begin to guess what size an engine is based on head casting number, or injector color, etc. Very possible that a cheap rebuild shop or local shadetree hilljack would put a set of 305 heads on a 350. Also just as likely that it could have injectors from anything on it. My 305 has 1988 350 injectors on it for example.

BTW, all the later 305s have a harmonic damper that 'looks' like a 350 damper, i.e. a little bigger. (iirc 7" vs. 6" or something, i forget offhand) Of course saying it 'looks' like a 350 damper is kind of a misnomer since they are bother internally balanced engines that use the same damper anyway.


But in conclusion, The ONLY way to know what the engine is is to read the casting numbers.

in front of the passanger side head on the small ledge near the corner of the water pump there is a partial vin# followed by a suffix code, see if the partial vin matches your's and you'll know if its the origional engine, if it doesnt match take the suffix code and look it up you may be able to tell what it is that way.. you'll probably have to clean off some grime though.. why not just get a small mirror and see if it says 5.7 of 5.0 next to the casting number???

also it running strong at 177000 miles dosent really meen anything either,alot of 305's live a looooooong strong life :D

If you really don't want to clean the case and read the casting number, you could simply remove a head and measure the bore. If it's 4", it's likely a 350. If it's only 3.73", it's likely a 305. If it's 4-1/8", you're looking at a 400.

You could also park the car sideways on a 45° angled incline, remove a spark plug, fill a cylinder with oil, then rotate the engine a revolution while catching all the oil that is displaced. measure the oil volume and multiply by however many spark plugs are screwed into the engine.

Like Ed said, head casting numbers, harmonic damper sizes, exhaust manifolds, underhood decals and stickers, and even cast core codes on the sides of the case are irrelevant.

LMFAO!! :D Vader, you're my hero. You've been cracking me up lately. Please keep the sarcasm alive.

Is the guy really that lazy? Sheesh............

I don't know for sure if this is right or not, but looking at my 305 block when it was out of the car, i noticed that, upside down, the side of the block only a few inches left of the fuel pump it had "305" cast into it.

dunno if that applies to any other engines though.

Re: Is it a 305 or a 350?
 

I had the same question earlier in the week and the only sure fire way to tell is this....
Remove the wiper motor (its real easy) . Only three 10 mm bolts to the firewall and one bolt on the other side to the arm.
With that removed get a light and a rag (for cleaning the stampings up). Look straight down the behind the valve cover, you will see either a 5.7 or a 5.0 stamp. There is your answer.
There really isnt any other way to tell.

Regards
Dennis

hello everyone, i wonder if ya'll could take a look at this pic and let me know what im dealing with here, i just picked up this z for a few hundred bucks and i have a feeling im dealing with an engine swap since i've heard that 86 Z28's werent available with a 350 v8 and a standard trans together. please check it out

http://www.cardomain.com/memberpage/513632/6

The '86 was not only not available with a 350/5-speed combo... it wasn't available with a 350!

The 350 wasn't an option untill 1987.

That does look like an unoriginal motor though, judging by the color (orange). The orange paint was used from 1955-77, after that was blue, then black in 1983.

It also has the drivers side dipstick too, which says that its a pre-1980 block.

OUCH!

do you believe that this is a chevy 350 though? since you say the engine predates 1980 it is possible that this is a 350 right?

Since its a pre-1980 engine, i'm almost certain its a 350. If its pre-77 (judging by the color) then its even more likely a 350.

Only way to know for sure though is the casting number. Look on the drivers side of the flange that the bellhousing bolts onto (on the block) directly below the drivers side valve cover. If the last three digits are 010, then its a 350 for sure.

awesome, thank you air

I don't know for sure but i think the oil dip sticks are on oposite sides!!

like the people said the otnly way to know if it's a 350 is if you look on the casting number.. can't really go by head casting numbers or injectors because i have a 350 (and i know it's a 350) and it's got 305 tpi heads and it's got a 305 throttle body with 350 injectors. heh

yea mine lasted for 170k before i blew a head gasket. then just decided to get a little better of one.

i thought that 305 harmonic balancers were hollow on the back and 350's werent or does this not apply to this year engine?

Well unfortunately, I have been bent over...
Someone sold me this trans am 5spd, w/ 305 telling me it was a 350 and believing him I bought it. I never thought to see if it really was. Since im guessing its an 83 and its a 5spd that 350 was not an option. So to make things right, he wants to give me a 350 from this old blazer. and i need to make sure this is a real 350. I want to look under the car but its flooded. I did notice there is a drivers side dipstick. Which in regards to a previous post its almost postive its a 350?
where on the block would be this casting number so i can find out the truth?

The oil dipstick on my 350 is on the passenger side of the car.

www.carfax.com ... type in the vin and it gives you the car type and engine type without a fee.

these posts are always too funny "350 balancer" "dip stick location"


oh and one I always get a good smile from is "oil fill hole on the valve cover"


keep them comming

easy one!
 

the 305 tpi cars came with the ac compressor on the passenger side and the 350's came on the driver side. So I have been told by the drivability guy at the dealership.


From what I have seen its true

Mine is a 305 and the AC compressor is on the drivers side...

lol 2 more location things... AC compressor now. lol, you guys are crackin me up too. Just get the CASTING NUMBERS. everything you guys are saying with locations are the same on a lot of 305/350 camaros/firebirds. CASTING NUMBERS, CASTING NUMBERS, CASTING NUMBERS

As long as it's not an engine swap

And mine is on the passenger side, I have a L98.
The only real way to tell is with the casting numbers, like several people have stated already.

Holy crap...lol

305 throttlebody... Hint Hint, the TPI system was designed for the 305,, the damn system is the same for both engines. The fuel tables are the same as well. The only difference is the injectors and flow rates.

The drivers side a/c compressor was pre 1988. Last year of the cold start injector was 1988. Passenger side A/C compressor was 1988-1992. 1990-1992Had an S/D system instead of a MAF.

Visiblily the 305 and 350 TPI cars are virtually indifferent, other than the knock sensor, part #'s on the injectors and block information. Small blocks especially 305's run forever, some on this board are pushing 350,000 miles.

The different types of Dipsticks for factory production are alright, but damn.

You don't need any casting numbers or anything like that...just measure the distance from the ground to the underside of the fender, since the 350 is heavier, it will compress the springs more, and the distance will be smaller than a 305, thats the best absolute way to do it, works every time. If the coolant reservoir is almost empty then it will always be a 350 since it need more coolant than a 305.

Thats great and all but I doubt he has two of the same year same suspension cars just with different engines....

:lmao: and my 383 sits higher than most 305 cars. :lmao:

Your joking... Right??

pretty long write up so I doubt it.. and your 383 would probably be about the same weight as a 350. Same block, larger bore(less mass), Large pistons(little more mass but less then taken from the block) and the crank.

A 350 is heavier than a 305??? What a dumbass comment. Do you realize that ALL small block chevy engines have the EXACT same external deminsions???? Thats right, A 400 SBC is NO "BIGGER" than a 283 SBC. The only differences are internal, and they are very slight. Mainly, the only difference is bore/stroke. There are enough variables in SBC's that there is NO way to tell what cubic inch an engine is, without checking the casting numbers (except for the 400sbc which is identifiable from the outside). So, a 350 that came with an aluminum intake from the factory is probably lighter than the 305 with a cast iron intake. Some SBC's had steel crankshafts, some had Iron. There is a pretty drastic weight difference there. Some 350's had 4 bolt mains, some did not... If you want to get technical, there is a weight difference there... Also, Your front suspension springs WEAR OUT over time and will sag. The alignment will also have something to do with your ride height. So, do you still really think that measuring old-*** spring height is a good way to tell what size of SBC you have? If so, your a dumbass and have no right to post on this forum again...

If the coolant reservoir is almost empty it is a 350???? Im not even going to comment on that one...

:rolleyes: lot of fun stuff in this thread....lol.... :lmao:

Hey Junior (tawd), it was just a joke...once in a while I post a sarcastic remark like that just for laughs, so lighten up a bit. Anyone reading this thread would realize that my post didn't "Hijack the thread"...it was posted long after Abird4u2nv1 had recieved many replies and suggestions... it was just a funny remark sinse everyone was comming up with different methods.

:lmao: That's the best one yet

Junior? Is that suppose to be funny? What is comical about that? I dont get it.

Its not my fault your a dumbass... Somebody probably said "lets see if this dip**** will believe this crap" and then told you that story about telling what engine you have by measuring the fenderwell. You, being the brilliant individual that you are, took it as gold and are now sharing your knowledge with us at thirdgen. Now that ive made you look like a complete dip****, you are acting like you were joking about your really smart fenderwell measuring idea. Even if you were really joking to begin with, your still an idiot...

I hope a moderator sees this and at least gives you a warning that you'll get banned if you keep on going with the name calling. :banned:

:hmmm: :idiot: :waveman:


Ahh both of you shutup...

really. its getting old.

hahahhahahah i had some dip **** tell me the same thing the other day about the harmonic balancer!!!! it's the same part number!!!!! tells me all the time... man you need to put a 350 in that camaro...why????? i think it is funny when people dog the 305 sbc.... it makes me laugh.... because 350's are soooooooooooo much faster......... :crazy:

pre 80 305's all have driver side dip sticks,

all pre 80 smallblocks had driver side dipsticks, displacement doesn't matter

Best way to know if it is not a 350.....When the seller claims it is one.:lmao: :lmao:

Great thread. Lots of laughs on this one! As good as standing around and listening to the comments at a swap meet or a show. :lmao:

Unless you start digging, my build looks like the original 305. The only apparent clue that it's something else is that the dipstick is on the wrong side, and even then it could still be a 305. After all, it's got side-bolt 305 heads on it. Most guys assume it's a 350, 'cuz you can't easily see the humps on the sides of the block. The balancer isn't a quick giveaway, 'cuz its balance weight is on the back side and the 305's pulleys bolt right up to it. One guy who did go to the trouble to check the side of the block assumed it was a 377, 'cuz as he said, "Nobody leaves a 400 as a 400. They always destroke it." Yeah, right.

Gotta love it. Even with casting numbers, the only ABSOLUTE way to tell the displacement is to pull a head and pull out the calipers. The casting numbers will only tell you what the block is, not what its present displacement may be.

I don't want to intrude but i wanted to add this little experience that a fellow camaro driver had with me.
He drives an 89 berlinetta, 305 v8, auto...

"I swear man, its a 350 look the heads have rounded edges."

As for tawd, I really do put forward my vote for his being :banned: because name calling and foul language really do no one any good on this forum.

Now back to topic, has any of the previous posters I.D. their blocks yet? I'm very interested on what they have found.

My friend had an 81 camaro with what he thought was a 305 until he got bored and check the casting numbers one today turns out he had a 302.

Sounds like the same old "Do I have a 2 bolt or 4 bolt 350???" Only way to tell is take off the oil pan and look. Only real way to tell if it's a 305, 350, 355, 383 is to pull the head and measure. Friend bought a 305, but it turned out that the guy he bought it from didn't know jack and it was originally a 350, but was now a 360. Check the casting number to find what the block started as...then if you really want to know, pull the head. I own three 350's theoretically. Two I know are 355's and one's an ls1 (346) with theoretically the original bore, I haven't pulled the head to check the ls1 yet.

Yeah, I checked the casting numbers on the back of the block before I bought it. The guy told me it was a 400, but I wanted to be sure before I plunked down my money. According to the numbers, it's a 400, cast in October of '76. That would make it a 2-bolt, originally in a pickup (no 400's in cars, and no 4-bolts, that year).

But the rest of the story couldn't be told 'til I opened it up. An Eagle crank with 5.7-inch rods (not the stock length). Stock replacement-style dish-top pistons with 4 valve reliefs, but obviously not OER, because of the longer rods. Chevy replacement 350 heads from about '76. Previous owner had had the motor rebuilt almost totally stock, except for the longer rods. 8.5:1 compression with a 300+ duration cam. No wonder the guy wasn't happy with it! My ported 305 heads with 0.051" head gaskets and a much better cam choice brought it to life.

Point is-- Unless you bought it new, or you take it apart, there's no way you can truly know what you've got.