307 to 403 Olds swap...info please?

[81X11]

Well here is the latest update on the Cutlass project.

This is the last year the Olds has to pass emissions tests, and the inspection is out tomorrow. I fired the Cutlass up last night at 9pm...after sitting since the end of June, all it took was three pumps on the gas, and the 307 came right to life. It sounded fine too, amazing it's shot. On the gauge cold it has 60psi oil pressure.

After sitting under the carport for a month it was dusty, so I drove to the car wash and sprayed the dust off. The car wash is about 2 miles away. Car ran fine, a/c blowing ice cubes and engine seemed fine, but when I got to the wash the oil pressure was below 30.

I sprayed the car off and wiped it down....it's SUCH a good looking old car, I just love it and can't wait to get it really "alive" again.

After the car wash, I drove to my mechanic buddie's house that's going to get it inspected for me. The plan is to inspect it cold, before it loses pressure and starts knocking. ANYWAY his house is about 5 miles from the car wash. Driving over I watched the oil pressure gauge slowly drop closer and closer to the red mark. Came to a stop a about a block from his house and the gauge dropped to nothing....doh. I pulled up in front of his house and opened the door to hear the lower-end tapping away. Oh well...

It should be inspected tomorrow, and once the new sticker is on the window, it's time to start pulling it apart.

-Mike

 

[81X11]

Oh, and after much discussion here and with some of my old techs, here is the engine swap plan..

I get the 71 Olds 350 this coming Friday. It comes home and gets put on the engine stand, gets cleaned, gets all new gaskets, a new front seal, gets a new timing chain, water pump, and a general once-over. We're also going to put in new valve stem seals, as it puffed just a bit of smoke when I started it in the 72 Cutlass last week after it sat for almost a month. And yes I am going to "bling" it a little with a fresh coat of gold paint and some chrome valve covers.

The engine has an Edelbrock Performer intake on it, and it's the EGR model with all the ports for the emissions controls. After going back and forth about this A LOT, I've decided to keep the car original and keep the computer.

Here is the method to my madness. To get rid of the computer, I'd have to get a new carb, new disributor, modify the transmission for the electronic lockup, modify the a/c system, modify the cruise control, and remove all that wiring without damaging the stuff I want to re-use.

If I keep it original, all I have to do is find some 1980-85 307 iron exhaust manifolds which have the larger ports and the 02 sensor ports. That's it. Everything else will bolt up as-is. ALL the vacuum lines have just been replaced, and the car has no check engine light on now. In other words, the hardest part of the swap will be remembering where all the vaccum lines go.

So that's where I am now. I'm rounding up new gaskets and such, and have to go get some new exhaust manifolds.

Will post pics as the project progresses.

-Mike

 

[Black Sheep]

Throw an oil pump on it, too.

 

[81X11]

Will add an oil pump to the list, thanks!

-Mike

 

[Minion1186]

If i was going to keep the computer and swap a different motor into my olds, I would personally take as many pics as possible, step by step to know where they all go...or get a tech manual with all the hose diagram.

I'm not anywhere close to an expert with the ecm/carb's on these cars but I have heard that an over the top cam with set codes off and make the motor run in a detuned state. I'd personally throw headers on it since the motors out but manifolds should do there justice.

 

[G-Body_Vet]

A '71 engine with #7 heads is a good score! I wouldn't bother with a squarebore Edelbrock carb though. I'd go with a running or rebuildable Q-jet instead and tune it (or have it tuned) for the application.

Olds 350's are great engines. I've heard of people retaining the CCC carb & ECM even on 403's. I think my major concern would be retaining the lock-up feature for the 200-4R. It can be done without the computer if you feel like doing the work. Not really a bad deal either. You'll love the power compared to the 307.

 

[Dragonist]

I currently have a non ccc quadrajet on my 350. I can take some pictures for you if you like. Also if you are unaware there is a conversion to my your dizzy hei...I'm running a stock ccc dizzy thats been convertored to hei. In regards to the stock exhaust manifolds you can use them, just buy manifold gaskets for 71-72 cutlass. I did the same thing with my swap, bring your olds gasket to the parts store and you will see the difference in the size!

 

[DoubleV]

Also if you are unaware there is a conversion to my your dizzy hei...I'm running a stock ccc dizzy thats been convertored to hei.

:? A CCC distributor already is an HEI.

Me thinks you're just running a CCC distributor with an aftermarket remote coil thinking that makes it an 'HEI'. If you're doing this with a non CCC carb, this is very wrong and needs to be corrected. It's been gone over a 1000 times; you MUST run a non CCC distributor with a non CCC carb.

In regards to the stock exhaust manifolds you can use them, just buy manifold gaskets for 71-72 cutlass. I did the same thing with my swap, bring your olds gasket to the parts store and you will see the difference in the size!

Just FYI, exhaust manifolds didn't use gaskets from the factory for his year engine, but yes, they do make em and you can use them.

 

[81X11]

Hi all! Went and paid for my engine over lunch today. Some good, some better, some bad....some new questions....well not too bad.

The bad is only that the engine is still in the '71 Cutlass at the shop. Neill's not had a chance to pull it yet, but since it's 1000 degrees I was not planning on doing much on my car until next month, so it's ok. It should be out next week.

The GOOD is it's paid for and as soon as it's yanked I can pick it up.

The BETTER is I was able to get some new info from the actual owner of the car. The engine was rebuilt about 6 years ago and the car is only a toy, so it does not have a lot of miles on the rebuild. He says it's always run fine since the rebuild, does not smoke ever, and the timing chain and oil pump were done, so I don't have to buy those. Good deal! He said when the engine was built it had some oil leaks and it went back twice to have those fixed, but it ran fine after that, it just was never as fast as he'd hoped so he's wanting a bigger engine.

He says the reason he's yanking was to put a big-block Chevy in the car, but Neill, my friend that owns the shop, convinced him to go with a 403 Olds, to make the swap easy. He was asking $750 for the engine on Craigs List but Neill got me a much better deal, which I'm happy about.

Now the new question, he said when they rebuilt it they put a "mild" aftermarket cam in it for a little more power. It runs smooth, not lopey, but I read if the engine is hopped up much at all it will not be happy working with the 307's computer controls.....so it looks like I may be back to the orignal plan.

We'll see. It's paid for, it's rebuilt, I don't have to clean it in the 100-degree heat this weekend. It's ALL good!

-Mike 🙂

 

[DoubleV]

As long as it makes good vacuum and the CR isn't too high, it'll work fine on the computer.

Personally, I wouldn't trust that engine to just drop in my car and expect it to run well, because if they're saying a 403 doesn't have enough balls, then somebody did something wrong. I'll bet the cam is not degreed and the CR is lower than the already too low stock 403 CR too, but then again I don't trust 99% of the people today to do anything right on a car. :wink:

Just make sure you're not buying a 'rebuilt' junk heap.