carbonf00tprint

Ok, I have read alot recently and understand that the smart money is spent on a larger displacment.
But
I would like to understad the diffeences between the chevy 307 and the olds.
Are the the same block, heads, intake, ect?
I searched and found many comparisons between a 307 and 305 or 350. But all these threads also speak of the 307 only comming with a 2 barrel carb.

I know thats not the case on the olds, so what gives?


Thanks,
Paul

SBORule

The Olds 307 is not like a Chevy 307, it looks just like an Olds 330, 350 & 403 on the outside, it shares the same stroke as the 330, 350 and 403 but it has a real small bore, I forget but something like 3.80" or something.

MDchanic

The Olds 307 and the Chev. 307 are completely different engines, like the olds 350 and the Chev. 350, or the Olds 455, the Poncho 455, and the Buick 455.

The Chev. 307 was made from about 1970 to 1972, if I recall, while the Olds motor was made in the early '80s, so carburation, tuning, emissions, etc. are all completely different as well.

- Eric

carbonf00tprint

It seems all the comparison I find for a 307 are chevy 307 compared to 305-350.
I'm looking at a car for my son and it has a 307 in it. Since I know little about motors in general, and noting of the 307, I felt I should read up a little.
It does seem that one thing both the olds and chevy guys have in common, most suggest not wasting time with the 307.

I wont be swapping the motor out though. The car is a numbers matching car, and I kinda would like to stay that way for the near future at least I think.

So, since all the info I have been digging up seems to be mostly for the chevy 307 I guess I need to keep searching.

I was looking for info on best parts for a rebuild, what combos for
crank/rod/piston for stroking it, ect.

I will continue to search, and if you know off hand a great link on said subject, it wont hurt my feelings if you throw me a bone.

Thanks,
Paul

Oldsmaniac

If you are looking for a late model Olds (81-1988) with a V8 Olds engine the 307 is your only choice. They run and power well but you wont find neck snapping or tire burning HP. The easiest swap would be to upgrade to a 403 small block Olds which can be built for tire burning HP. More cubes =easier HP to obtain. If this doesnt float your boat perhaps a Chevy or Ford may make things easier.

Oops forgot the 89 and 90 Custom cruiser wagon with the 307!

MDchanic

I doubt you'll find any.

With 350s and 403s so easy to find and build, there's really no demand for for doing anything to the 307s, aside from tying a float to them and using them to anchor boats.

I would bet it's even difficult to find standard-quality stock rebuild parts.

- Eric

carbonf00tprint

I'm not a car guy, but my son loves what I think are G bodies.
grand Prix, Regal, Hurst, Monte carlo.

His fav, is regal, but not a v6, he wants to spend all his cash in fuel.
( may as well let him learn early, and get it out of his system )

I stumbled across a hurst, and would like to keep numbers matching, so that rules out an engine swap.

Just looking to figure out how dependable the 307 really is, and what options are on the table from past experiences for improving the core ( stroking )

also alot of what I read about the 307 said it was a ???/webed block? sht I dont rememebr.
Basically said it was weak at higher power/rpm
Is this the case with the olds 307 aswell?

Thanks

1970cs

The Cheby 307 was made 1968-73 3.875x3.25. I remember my close family friend they had many Oldsmobiles, but they also had a 68 Impala with a 307 in it.
Oversized heads and headers and side pipes and baby moons for wheels, cool car but light metalic green.

Like the others have said the Olds 307 is a good runner but, not a powerhouse, I had an 87 442 with the H.O. 307 and 3.73 rear, the whole car could not hold a candle to my 70 Supreme 350 and 2.73.

A little side bar here, I live very close to Lansing and one my child hood friends dad was an engineer for Olds and they (engineers) were messing around with a mid eighties Cutlass with a 403 in it, I was able to talk him into bringing home for me to ride in, I was around 15 years old around that time frame. I'll tell you that really wakes that car up!

Pat

Oldsmaniac

The widowed main webs are on the 403, not sure about the 307. Nothing to worry about for a street engine. If you were to get a 83-84 Hurst and are concerned about molesting it I would suggest leaving it alone (307) after removal for an Olds 350 or 403. Comes time to sell the car the 307 can be safely put back unbroken and unmolested. Dont over think things here or try to overbuild a daily driver. This doesnt usually work.

carbonf00tprint

I prefer keep the numbers matching, dont want to put too much power in his hands either.

I wont be doing anything anytime soon anyhow, but I want to absorb as much info on the 307 as I can. It appears most info I found was for the chevy 307, so I started of confused already, and found some build kits/threads for that block.

Now that I realise the 2 are noot the same, I just have to stumble across the right thread/web site for the info I seek.

Its out there, I just got to get lucky and find it.

Lady72nRob71

Carbon, welcome to the forum.
If you got a Hurst, then it should have the VIN 9 307, which was the 180HP version. This one is more desirable from a performance aspect. The regular VIN Y used in all the other applications was only 140HP.

Try exploring oldsgmail.com for additional info on these cars.
Here is a popular post to help maximize the output of the 307...
http://tlentz.oldsgmail.com/more_power.html

If your son likes the Regal, then he would love the Grand National! I wish I got one long ago...

carbonf00tprint

Thank you, I see your in Plano, I grew up in Celina just north of Frisco.
I saw a Vist Cruiser for sale down the road just the other day, I will go by next week and give it a look for you.

My son does like the look of the grand national, but he likes the rumble of a v8, kids got to pick his poison.

edzolz

Just to let others know where you are, please go the User CP and post a location.

carbonf00tprint

http://performanceolds307.tripod.com/id1.html

Thanks lady for the info

in this page, it talks about " limp home mode "
will a engine light be one in this mode? I would assume so, but I often
assume too much.

will do when I have some time, doing alot of reading and now its time to eat

Lady72nRob71

The service engine light will supposed to be on if it is functional. It should likght up when key is turned on. Limp home mode is where the car will run but the computer is not controling any of it, so performance will not be good.

OLD SKL 69

Welcome to CO! To chime in on the 307 Olds, I have owned 2 cars with these motors. My first one I bought with 25k miles on it and sold it with 204k. Only did a timing chain, and that was preventative maintenance around 170k. Good gas mileage, consistently 20mpg+ in an 85 Riviera on the highway, did not burn any oil and exceptionally good running and reliable. Good choice for a driver.

joe_padavano

ALL Oldsmobile gasoline engine blocks from the 1977 model year onward were lightweight windowed main web castings with 1/2" head bolts. That covers 260, 307, 350, and 403.

And to the OP, your 307 is an OLDSMOBILE motor. Chevy parts don't fit and Chevy comparisons are irrelevant. It's a lightweight, thinwall, low-performance casting and there is very little you can do to increase displacement for a reasonable amount of money, short of swapping it out as others have suggested. SBCs came in several different stroke configurations, so mixing and matching cranks is easy and relatively inexpensive on those motors. EVERY SINGLE small block Olds motor ever built uses a 3.385" stroke, so there are no drop-in stroker cranks unless you have one custom machined at great personal expense. The thinwall block makes it impossible to machine a meaningful overbore, either, and the heads suck in any case. Sorry, but that's the way it is.

carbonf00tprint

Me and my son left today to go get the car, got there and it was worse off than described. Lots of issues not shown in pics, so we drug a trailer 5 hrs for nothing.

motor was much worse of than I was expecting
undercarriage had lots of flacking rust, and evevrything had significant surface rust.

Interior was not as good as expecting, but workable for sure.

body was about what I expected, but none of the pics showed the spidered crack in the winshield.

My main issue was the undercarriage, it was a deal breaker for me.
I think the cars rust underneath means it needs to be striped to the bones.

I dont wasnt to do that, its to much project. I have already seen cars just a few grand more in much better starting condition.

Thanks all for your input, it helped me make a more informed decision.

joe_padavano

Sadly I've found this to be all too common, either due to ignorance or willful misrepresentation on the part of the seller. I once drove 17 hrs round trip to pick up a "rust free" Cutlass shell, only to come back with an empty trailer. I'm especially skeptical of cars that have been repainted and are advertised as "no rust visible"...

I've pretty much sworn off even looking at cars from the rust belt. It's worth paying the shipping from the desert southwest.

Run to Rund

x2 on desert southwest cars. From what I have read, serious frame rust and body rust are common on G bodies. It is no bargain to get a car that needs 3 tubs of bondo and $10K in body work to cover up rust holes, compared to finding a rust free car in the southwest.

olds 307 and 403

Supposedly, the 307 can take a large over bore. Doesn't matter, custom pistons and offset ground crank still equals small displacement. The 403 has all the short comings of the later blocks except a HUGE 4.351" bore. The torque improvement is big compared to a good running 307, had a couple. A Hurst/Olds in good shape is going to cost much more but will be worth it.