A while back I was the one who posted in here that I was going to be putting a 455 Oldsmobile in my '86 Firebird. I'll give an update on that, in case you care, and then get to my question.
I FINALLY got the motor back a month ago. It makes well over 500 HP and around 580 ft/lb. of torque at around 2500 RPM. It looks rather simple though, it's all red, with not a chrome piece in sight. I just ordered an Edelbrock torker 2 intake and edelbrock q-jet to put on it. The motor is about ready to be dropped in the car, but my tranny guy, 3 months later, still isn't done! (of course it doesn't help that I've been in Spain for the last 30 days either....)
Now onto my question. THe motor mounts! I called summit to get motor mounts and they said "nope, can't do it". The sales rep. recomended getting motor mounts from a '78 Firebird with a 403 Olds... WHAT? A factory Pontiac Firebird that came with an Oldsmobile engine? So I wasn't the first with the idea.... I guess my question is, what do you people recomend? I've contacted Mondello for a conversion, if they have one, but no reply as of yet. Any ideas? If I don't get anything from Mondello, should I try the '78 and then go from there? Thanks!
John

 

buy something to fit the engine, buy the lower to fit the upper and weld the lower to the k member

 

I'm not that great of a welder first off, and second reason is I don't want to weld it into my engine bay. That's too permanant. I would have to get a cutting torch to free it up later, if I ever needed to pull the engine...

 

76 or 77-79 or thereabouts Firebirds could have a 403 under the hood. If those mounts will work or not in a thirdgen, I dunno.

 

I've still haven't heard a definate NO the 455 will NOT bolt right into the same place as the 305. The 454 and 305 would, I think, so maybe I can get lucky...

 

hi there. The pontiac trans am introduced a 403(it has the same mounts as a 455) i think in 78-81. It was an engine option along with the pontiac. If you find a 79-81 pontiac trans am with an automatic tranny then there's a big chance you might find an olds in it. the 403 motor mounts are the same as the ponty 400 but they attached an adapter to it where the mounts attach to the block. I had a picture of one but can't find it.
hope that helps.
cant wait to see that olds under your birds hood. I have a pontiac 400 fully rebuild pushing out a modest 400+ ponys and 420+ of torque that i want to install in my bird but i want to get all the info first before hand.

 

Thanks for the info. Where can I find one of those adapters? Will I be searching some junkyards? Also, what year is your 'Bird?

 

403 option died in 79, know that one for sure. Just FYI.

 

Well now I'll just be searching for '78-'79 Firebirds then... Unless there is a better way. What was the engine code for these combos? How will I know it's a 403 Olds. and not a 400 Pontiac??

 

IIRC, the 403 olds powered cars said "6.6 Litre" in 79. I don't know much about olds motors but pontiac motors are fairly distinct looking.

Maybe this will give you a clue:

http://my.inil.com/~dlbrown/ofe403.h...IDEngineDetail

 

The number 1 dead giveaway is the oil filler neck. For some reason Olds put them right smackdab in the front of the intake manifold.

I would guess they did that for all the nearly-deads so they could see it, and reach it easier.

AJ

 

what in the hell are you talking about welding the lower is too permanate? the upper and lower are still bolted together. if you can't weld find someone that can.

 

OK, I'll give you a definite "NO": Olds motor mounts are different from Chevrolet ones. You can't use Chevy V8 mounts (262.5 / 265 / 267 / 283 / 302 / 305 / 307 / 327 / 350 / 400 / 366 / 396 / 402 / 427 / 454 / 502, they're all the same) mounts on an Olds motor. Yes the 454 and 305 interchange, because they're both Chevy motors; the Olds will not, because it's an Olds, not a Chevy.

Not to be a jerk or anything, but the exact wrong way to approach a motor swap would be to get a motor built, then harangue people on the internet about what mounts to buy, when you don't even know what kind of cars might have come with something close. And, the exactly wrong way to research this sort of thing is with "engine codes"; you do it by opening the hoods and looking. An Olds motor and Pontiac motor are so different to the eye that they are impossible to confuse.

You'll definitely be scouring some junkyards. You'll be looking for 2nd generation Trans Ams, which should be plenty specific enough, it's not like you're going to go somewhere and see acres and acres of them sitting there and need to narrow your research. Quite alot of the late 70s ones came with Olds 403s; those weren't very good motors, not nearly as good as alot of other olds motors, but the parts they used to assemble the cars may either fit your situation, or give you some raw materials, or at least some ideas.

While you're doing the research you should have done before you started, start looking into an exhaust system, i.e. headers... that's the next thing nobody here will have the faintest idea about, because it's going to be completely different from any other exhaust system ever created, and no, a Chevy or Pontiac one won't work. It's going to be a custom, one-off kind of thing, and it won't be easy or cheap or quick or trouble-free either before or after the fact. Same goes for all the accessories on the front of the motor.

No chrome sounds just fine to me... that crap doesn't make the car one milliseond faster, or function better in any other way; it's just wasted money IMHO. I prefer a strictly business kind of look, and leaved all that other stuff to the street rod guys, who will put polished 6-71 blowers and 2 chrome carburetors on a 78 305 2-barrel long block because the long blocks all look the same.

 

easy there man, it'll be ok

 

I have a 403 in my 78 trans am
The two easiest ways to tell it's an olds is the filler neck, it is a long tube at the front of the engine,and the distributer does not go through the rear of the manifold into the block.
PS. the engine code for the olds is (u2.u3,va or vb).
Hope this helps.


Jeff

 

RB83L69 I did realize the engine mounts might cause a problem however I must admit I didn't realize it wasn't going to be as tasking as it is.... I realize also the exhaust is going to be a problem, that is why I have kept the exhaust manifolds and will use them until I can save up the money for custom headers. The front of the motor, the accesories, hasn't been that much of a challenge. I can use most stock parts, alternator, water pump, etc. The engine bay is big enough, it's just those darn motor mounts... I apologize if I've been nagging to anybody here, but if you don't want to help me do something original then don't post, it's as simple as that.

 

ede I'm sorry I TOTALLY misunderstood what you were telling me about welding... For some reason I was taking it as welding the two together, then I WOULD have to cut them apart, but I see your point now. Which is actually a VERY good point. I could get someone to weld that on for me. So now all I have to order is some engine mounts for an Olds. 455 and then the lower will come with it and I just weld it on so it matches up with the top. That's a VERY good plan, I never would have considered it. KUDOS!:hail: I think I'll go order some motor mounts now... Anyone else have any input on the subject?

 

Why does everyone insist on going to junk yards for mm? We are just finishing up a swap and found that remove replacing the mm was the biggest pain of the swap. If I was to do it again I would by new ones at the parts store. Autozone had the right trans mount for the 700r4 ( diffrent from v6 to v8) for $6 the mm for $13. why cant you do the same go in ask for a mm for 78 t/a w403.(ps the mm we used came from a 78 camaro)

The swap is relatively easy the most time so far has been spent rr mm and finding the right combo of fittings for the mallory regulator to factory gas lines, but 3 stores latter at home depot I found the last ones I needed

ps take out the distributor before installing wouldnt go in with it on :-)

 

You don't go to the JY to buy them, you go to look at them... that way you know what might fit, or what might be suitable raw material to make something out of, etc.

I didn't mean to sound harsh, only it's really irritating to see somebody trying something unique and one of a kind, and expecting step-by-step instructions with part number lists, and not understanding that ALOT of custom engineering goes into a motor swap like this. Most of the time, you could get the whole motor for free, and it will end up costing you more to cram it in than it would to buy a junk small block Chevy and drop it in. Plus, a swap job like that is never ever as reliable as one designed to fit; not so much whether the motor itself will last, so much as the sheer difficulty of making all the parts strong enough not to break, getting everything to line up perfect and stress-free, etc. Unexpected things like power steering pumps hitting steering gears, valve covers hitting power brake boosters, exhaust hitting steering columns, oil pans hitting steering linkages, water pumps that are too long to go between the block and the radiator, are the norm with swaps like this. Expect the unexpected, because it will surely happen. The more research you do on the front end, the less likely you are to get tripped up by some total incompatibility down the road during the project. You have no idea how many hack jobs I've seen where people have put stupid things in cars; one good example was a 69 Chevelle SS we bought once, where somebody had put a 283 in it; they swore up and down that the mounts for big and small blocks just had to be different, because the ones they had wouldn't line up. Turns out they had a full-size car oil pan on it, which if they had known what they were doing they would have been aware was a different shape, and the pan was just sitting on the frame, so the motor lacked an inch of installing; so they welded the mount halves together. It was a real joy getting that motor out of there.

Do your research!! Measure everything!!!! Get familiar with all the variations of all the parts you might use, so that when you see the hole, you know what fits there! You can't get that kind of knowledge by badgering people on the Net.

 

I agree that u cant expect a step by step instruction formatt with part #s. Im not saying u(RB83L69) specificly but alot of post that I read when I first found this site in the archives said real negative things about doing swaps from v6s or odd swaps such as this. I almost had my son sell his car and go to something else because of it and it turned out (so far) to be easy enough for a 17 year old to do everything except the fuel plumbing and the wiring for the fuel pump and fan.

I guess what Im getting at is let people know that things r possible that it will take so engineering some times but if u have the patients resources and inginuity go for it u might actualy learn something ( in my case get closer to a son ) gain more pride in your ride and be unique.be carefull what u write to many people beleive everything they read on here.

Ive apreciated all the help Ive recieved expecially that bone head question u all answered thanks again im sure ill have more

 

By the way the reason I even read this post is because my cousin had a 2nd gen with an olds engine that was running in the 9s.
what r the possibilities in a 3rd with less weight?

 

Well I know I appreciate all the comments, both good and less than good, because it just prepares me more either way. I FINALLY got a reply back from Mondello informing me to buy there "TA 350-403 motor mounts." So I'll order that from them and that SHOULD allow it to bolt in, with a little less difficulty than before. My biggest concern now is the power steering pumps and whether the exhaust manifold on the driver side is going to hit anything... I guess I'll measure and find out!
On a different note though, I am having to get a new cap and sending unit(the unit that relays the gas amount to the gauge AND the cap that gets the fuel to the fuel line and it has turned out to be a CHORE! NO auto parts store even offers it, the dealer ship told me it's discontinued and 3 salvage yards have told me "nope, don't have it"!!!! mad: It's just a sending unit from a gas tank! I guess I'll be hitting more up tomorrow. Thanks again fellas' for all of the help. By the way, what kind of Olds. motor did your brother have in his 2 gen. F-body? If I can get traction this motor should put me in the 11's, and when I put a blower on it, I'll for sure be in the 10's... Of course putting in a roll cage will be a different story.
John

 

Can you get some info about how he swapped in the olds Rocknrods.

I have a pontiac 400 I want to swap in but I know the problems about the headers but if I could use plain exhaust manifolds then I don't care. I'll get custom headers later.

good luck in your swap in also

 

Sorry doomsday cant help u out there he has moved out of state and I dont know how to get a hold of him except through his mom and we dont get along too well. I do believe that it shouldnt be too tough the 2nd and 3rds have the same cross member bolt paterns and u could get the bb pontiac in the 2nd. as u said though u might have problems with exhaust stearin.
thanks for the good luck it fired up no problems last night just have to test out the tranny tonight.

Oh by the way he did have to get rid of his car cause even with frame straps he twisted it up bad. Shouldnt have put it in a t top car!