olds 307 to olds 350 swap.

huh

 

I know that it's super easy to take out the olds engine and put in a Chevy. I just have to make sure the tranny housing fits, chang the engine and tranny mounts, driveshaft, frame mounts, wiring, exhaust manifolds, throttle cable modifications, transmission cable alterations, accessory mounts, fan shroud, possibly moving the crossmember, swapping the starter and alternator, and get all new belts! Oh yeah, that'll save me a ton of time and money!

Seriously, why do people keep trying to tell me to just put in a Chevy? Is it just that y'all love Chevy that much?

 

Can you hear the gently used engine run? This sounds sensible to me. The engine is barely broken in.

 

The fuel mixture and spark curve are designed for the smogger 307. You CAN use the CCC with a larger engine, but you need to burn a new PROM with the correct fuel and spark tables. For example, the spark advance assumes EGR is working - disabling it caused pinging. Also, the CCC carb on the 307 has a stop that limits the secondary air valves to 70 degrees opening. You need to file this stop to get the full 90 degrees.

 

I was not aware of the price increase. In 2013 I bought a 350 Vortec short block, 350 HP from Jegs for $2300.00 . Looks like I got it in the nick of time. I'd still buy the crate.

 

Not everyone is a lemming.

 

What do you all think of this?
How much of the information on this page is aimed solely at those car owners who are looking for max power from their engines, regardless of MPG?

What is the difference between windowed and solid main web? Would that difference matter to someone who isn't looking to build a race car? I assume the windowed main web engines are cheaper than the solid ones?

http://www.442.com/oldsfaq/ofe350.htm

I mean, if my 307 in it's prime was getting 140 hp, and 245lb torque, I would think 180hp, 275lb torque would be a nice change. What would that do to MPG though? As long as I'm not wearing my lead shoes, would it be greatly noticeable?

Would a 1974 olds 350 have any/many compatibility issues with an 81 wagon?

 

First, you need to understand that the info on 442.com is NOT always correct. That FAQ was compiled from a bunch of posts on an Oldsmobile listserver in the 1990s and no fact-checking was done. The site is now owned commercially and there is no way to correct the bad info. There's a lot of good info also, but it can be very difficult for a novice to sort the good from the bad.

Second, any Olds 350 is an improvement over the 307. The 1968-76 motors have the stronger solid main web castings. All 1977-1980 350 gas engines have the lightweight windowed main webs in the block. The "windows" are lightening holes cast in the webs that hold the main bearings. This reduces weight and strength. Frankly, unless you are building a 350+ HP motor, you'll never see the difference in a street-driven B-body wagon.

Third, the bigger issue is the cylinder heads, cam, and compression ratio. The 1968-72 heads are better, and the 1971-up heads have factory-hardened valve seats for using unleaded gas. Olds varied CR both by using different combustion chamber volume and different piston dish size, so you need to pay attention to both. On the 72-earlier heads, chambers are all about 64 CCs or so. Later smog heads can have up to 80 CC heads.

The reality is that you will likely not have a lot of choices in what motor you get unless you jump into the Olds community and start asking around.

 

I have an '87 Buick LeSabre Estate Wagon with the afformentioned Olds 307 and the venerable Turbo Hydro-matic 200-4R transmission. Having a BOP bellhousing, is this not the same transmission as found in the Grand National? If this is the case, would a direct swap with a Grand National (231c.i. 3.8L) be possible? Which rear end would you use? The 7.5" 3.42?

My engine only has 84,000 miles on it, but it burns oil at an astonishing rate of a quart every tank of gas. I have used the Lucas Oil additive twice, but with no real improvement. The internal seals have probably gone bad, and being such a dog of an engine, I really don't want to tear into it when I can probably replace the whole thing for just as cheap.

 

Gee, only sort-of hijacking this thread...

Yes, it's a BOP case. Actually, it's a Unisex case with the Chevy bolt pattern in addition to the BOP bolt pattern. Yes, it's the same 200-4R CASE used in the GN. Obviously the internals are beefed in the GN application and the valve body is programmed differently.

Yes, the first gen 3.8 liter Buford six bolts in - it was factory available in the B-body cars. You probably don't even remember the LeSabre Turbo Coupes built in the late 1970s. Of course you need the correct Buick frame and motor mounts. You'll obviously also need all the wiring, computer, intercooler, plumbing, etc, etc. Dropping in an older Olds motor is MUCH less expensive, as the OP has already figured out.

By the way, the B-body wagons already come with the stronger 8.5" rear axle, as did the 85-87 GNs.

Here's the LeSabre Turbo Coupe.

 

Hey, sorry for that. I should have started a new thread, or better yet, read prior threads, before just jumping in. I saw "307" and "swap" and my fingers took over where by brain left off...

Thank you for the info. I'm trying to figure out the best way to increase efficiency and eliminate my oil burning issue in one action. This is all helpful. Also... Yes, I had heard of the turbo LeSabres... Just have yet to see one in person.

 

I saw one. You're not missing much. Now a Grand Nat, that's a sight to behold.

 

First poster on my wall growing up.... Came close to buying one, only to find out it was just a re-apholstered '84 Turbo Regal. Not worth the $9000 asking price.

 

Clones...the bane of automobile ownership.

 

Since we've driven this thread off the road, across the median, and into oncoming traffic, I'll point out that the car to get in that time period wasn't the GN, it was the T-Type. Same car, same engine, but stealthy. Also available in colors other than black.