arnoldjr

Hi, Arnold here.
I recently purchased a 91 Pontiac Firebird for a project. Has the 5.0 tbi. Yesterday I picked up an Olds 350 from a 72 Cutlass that still runs for a whole $80. How hard is it to replace the 5.0 with the Olds 5.7? Any help will be appreciated.

oldcutlass

Now heres a switch, lol!!

You will need to change motor mounts and mounting brackets, wiring change for starter as its on the left side, hopefully your 350 came with all the accessories, and pulleys, headers and exhaust mods. You will have to mod or replace the trans, and the driveshaft may need to be modified.

joe_padavano

First question you need to ask yourself is, do you need to have the car emissions tested where you live? This swap will not be emissions legal and may be failed by an inspector.

Assuming you don't care about that, there are no existing frame mounts for this swap. You will need to custom fabricate them. You MIGHT be able to use the block-side brackets from a 1977-79 Firebird with the Olds 350/403 motors. These brackets will let you bolt an Olds block to the Chevy clamshell frame mounts. You'll need a new trans (due to the bellhousing bolt pattern difference), new accessory brackets, pulleys, exhaust, starter, etc. Of course you'll need to change the fuel system as well.

I hate to say it, but you'll spend several thousand dollars to install that $80 SBO.

arnoldjr

arnoldjr

The 350 came complete all pullies carb exhaust manifolds etc. I also have the transmission though I'm not sure what they came with and driveshaft as well. Being the mounts were bolted to the cross member and I have those as well could I simply rebolt them in the firebird and mount that way?

oldcutlass

Possibly, what you would have to do is set everything in place and see if things line up. You will have to do some fabricating and a little research!! As Joe said, your $80 motor may cost you big $$$$$ snd/or alot of time on your part to get in there.

I was browsing around the internet and found some SBO installs in Camaro's and Firebirds, so it has been done before!

I don't think it will be as easy as doing an A/ or G body sbc or bbc swap!

Good luck!

arnoldjr

Ok thanks for the help. I figured it would cost a few bucks to get done but in my mind I'm already ahead. Got the totally rust free car for $400 because it wouldn't start. Simple vats bypass fixed that. Also how attainable is my goal of 300-325 horse? And where is a good supplier of performance parts?

joe_padavano

The crossmember may or may not be the same width and may or may not be in the same location front-to-back. The steering linkage may or may not clear the oil pan. The driveshaft will almost certainly be the wrong length. I'm not saying this can't be done, but it is far from a "bolt-in" operation.

arnoldjr

Ok thanks. Looks like Ill have to take measurements of everything. Guess it's called a project car for a reason lol.

Oldsguy

Welcome to CO and so glad you are willing to put forth the effort to do the swap, it will take some effort. Like was said earlier, 'there's a switch!' we see quite a few questions about changing SBO to SBC.

Fakser

Your gonna have to get creative on this but it's doable, hell with the right tools I could swap a rhino horn on a buck and put the buck antlers on an alligator. There are tons of projects like this try and reference hot rod, carcraft and similiar magazines. I'll bet if you check there sites and do some searching you'll find something similiar. It's a good start to have everything. Check your toolbox do you have a welder, grinder, access to a machine shop for that driveline and on and on then make a plan for how it could go in. Once you get a good Idea do your measuring. Draw up where the motor will mount make a mock out of cardboard or some thin wood. Once you feel comfortable that you've got all I mean all of your bases covered.........DO IT and reap the bragging rights because if you pull it off thats a neat project worhty of them.

OLD SKL 69

Welcome to the forum! Interesting swap, keep us posted.

svnt442

Here's my $.02.
Keep the trans you have and get an adapter plate for it to use the BOP engine because you won't find a BOP trans with the torque arm mount on it because they never made one.

arnoldjr

Thanks.
I have a welder, grinder, plasma cutter, duct tape, and my friend has a machine shop so I think i have the tools necessary to get it done. Also tell me if this is correct. I heard that some cutlasses came with a chevy 5.0 and the swap didn't take too much. So i was figuring if my firebird also has 5.0 then the cross member should be the same width/distance front to rear as well, making the swap also very much doable. Make sense?

arnoldjr

Do you mean keep the trans from the firebird?

arnoldjr

One more thing. What does the #7 head indicate?

svnt442

Yes.

arnoldjr

Whats a torque arm by the way?

joe_padavano

Sorry to be brutally frank here, but questions like this would indicate that you need to spend some time getting educated about your car before launching into a major mod like the one you're talking about. Get a factory service manual for the car and study it first. You're talking about a swap that results in changes to many of the fundamental systems on the car - suspension, fuel, etc in addition to the engine and possibly trans. Starting a project like this without doing research first usually ends up with a disassembled car that is later sold in pieces.

And look under the car. The torque arm is the suspension link that runs from the trans to the rear axle and affects suspension geometry and driveshaft if it's changed.

arnoldjr

I actually had an idea the torque arm is the long bar running from the transmission to the rear end. And also the swap will not be nearly as hard as you are making it out to be. Being there is multiple holes on the cross member and it is the same width the mounts from the cutlass were able to bolt right on in the proper place I need them. Also, the motor mounts on the sbc are closer to the front of the motor then the sbo. But low and behold the sbo has 3 bolt holes on the side of the block to move the mounts forward to make them in the same place as the sbc. I already have a th350 with the mounting holes for the torque bar all I need is the $70 dollar adapter plate that is sold on ebay to make it work. As far as the fuel system that part is easy. Maybe a little time consuming but easy

chequenman

Hey Joe, you can only be nice for so long, and then you pick up your tools and GO HOME!!!!

70 cutlass s

The other holes are for V6 motor mounts 2.8, 3.1 and not for an Olds engine.

I built a 84 Camaro back about 17 years ago put a th350 in it. I bought the B&M adapter kit to make it work. Trust me you would be better keep the 700R4. The most bang for the buck would be to put a 350 Chevy in this car everything would bolt up and it would be a easy swap.

The words "80 dollar running 350 Olds" raises some alarms. This 80 dollar engine will end up being a 3,000 rebuilt engine before its over with and you can bet on that. You just don't something for nothing, not anymore.

When I built my Camaro I went from a 2.8 V6 to a 350 Chevy after it was all over with I wished I would have just bought a V8 Camaro to start with or better yet bought a Cutlass/442 and not wasted my money. I end up spending more money then I would have if I bought a running car.

arnoldjr

I think I will have to get a different 700r anyway. It like slips into gear under heavy acceleration. And by heavy I mean all 170hp the 5.0 puts out lol. I want to put the olds 350 in just as something different. I guess in the end if I can't get it to work there are sbc everywhere I could get and put in. But for now I'm determined to get it done. As for the engine it looks in very good condition I already tore it down. I'll post pics to get your opinion.

TK-65

Get another small block chevy to put in it, they are so easy to find and much easier to install than the Olds. I dont get why people are okay with this swap but bust a spring when someone wants to put anything other than an Olds in their Oldsmobile.

junqueboi

AMEN...

IMO, unless you are some kind of seasoned mechanic/fabricator, I would avoid the swap...the car will never be right with all the rigging that would have to be done.

Is being different just to be different worth the cost of having a POS F-body? As an owner of a '90 305 TBI/auto Firebird & '89 305TBI 5-speed RS Camaro, I can tell you that these cars in stock form are very nice reliable drivers (Camaro > 180K with zero drivetrain repairs other than water pumps/alternators). Find a junkyard Chevy 350 & you'll end up with quite a fast car. You can even keep the TBI if you go the Chevy 350 route. TBI is an incredibly reliable & economical setup in my opinion.

If you were able to score that Olds engine so cheap, you can probably score a nice G-body project car cheap also. Heck, you could be "different" & choose a GP or Regal or Monte Carlo....and the swap would be incredibly easier/cheaper. You could make the engine look & drive like it belonged there and NOT have to buy adapter plates, screw with WIRING (lots of wiring), clearance issues, etc. G-body cars have a more rigid body-on-frame structure anyway.

For example, you find yourself a T-top Grand Prix/Monte/Regal/etc, pull the engine wiring harness & motor mounts out of any 307 Cutlass & it's plug and play. Many mid 80's Regals had 307 Olds engines from the factory & your engine would be a literal bolt in affair (1 weekend's worth of work).

Heck, you could find a 70's Nova or Phoenix or something & use your engine in one of those cars (the 70's Seville was based off the X-body platform & they came with Olds 350s) so that's a viable option too.

On the other hand, I think some guy on oldspower put a 307 in a 3rd generation Camaro so I know it can be done (I keep asking myself WHY though).

Oh yeah...good luck trying to fabricate true dual exhaust on the Firebird if you choose this punishment