1955 Pontiac engine question

[1955Chieftain]

I want to put a Small block chevy motor, preferable a crate motor possibly the 350 fuel injected engine they sell I think its called the Ram Jet, into my 1955 Pontiac Chieftain (American model.) Whats the easiest way to do this? Do they sell aftermarket motor mounts to put a SBC in? What about transmissions etc? What problems will I run into. Any help appreciated.

[1955Chieftain]

I want to put a Small block chevy motor, preferable a crate motor possibly the 350 fuel injected engine they sell I think its called the Ram Jet, into my 1955 Pontiac Chieftain (American model.) Whats the easiest way to do this? Do they sell aftermarket motor mounts to put a SBC in? What about transmissions etc? What problems will I run into. Any help appreciated.

[Bill Eveland]

Hi 55 Chieftain, welcome to the group.
The last 55 I saw with a Chevy smallblock had a front mount installed. It's used a front plate mount similar to what Speedway Motors sells, they have a website that shows their mounts and accesories.
They used rubber isolators from the front plate attatched to a welded fixture on the front crossmember. Again , Speedway Motors should have what you need to mount the front of the engine.
You'll have to make a rear mount for the trans, either th-350 or 400 as long as their short tail shaft to clear the x-frame.
You will need to make a middle support also, you don't want to have just a front plate and trans mount or you have a good chance of breaking the tailshaft. Try to tie into the original trans crossmember to some of the transbolt holes.
A driveshaft,trans linkage will need done, something else as far as the exhaust goes, you may need to use passenger side manifolds on both sides to clear the gearbox and master cylinder on the drivers side, If the 287 is still in it , you can see how the exhaust needs to be routed on the driverside. Dual exhaust is tricky especially around the under seat floor heater.

[1955Chieftain]

Aren't front mounts really not good for a newer motor that would make around 350 hp? I thought that you were supposed to use side mounts. If I wanted to use side mounts how would I go about doing that? And do you think the 700r4 transmission would work with how the x-frame is made? Thanks for the help Bill! http://forums.performanceyears.com/groupee_common/emoticons/icon_biggrin.gif

[Bill Eveland]

Fyi, Pontiac used front engine mounts up thru 58. My uncles 58 Tri-power Superchief hasn't had any problems with his front mount.
I made side engine mounts for my 55 using 2" square tubing and some 1/4" plate . It's tricky on the drivers side because of where the mount need to be because of the gearbox is on the frame at that point.
The 700r4 should fit, it's about the same length as a short tail th-350. With that much hp, you may start looking into a differant rearend also. 49-56 rearends don't have a posi and come with 10 spline axles and arent made to hold to a strong engine.

[carzan]

The 700r4 fits nicely. requires no firewall or floor modification. Mounting rear of trans is simple, made my own cross piece out of 2' square tube, used a stock trans mount. Mounts for engine definately the challenging part.

Rear end. I've got one I'd sell. Narrowed '97 chevy 1/2 ton with 8.5" 10 bolt posi currently together with 4:10 ratio include 3.73 ratio. Pro street axles. Width is correct for '55 using rims with zero offset/ 3.5 backspace on 6" wide rim.

Edward

[1955Chieftain]

Bill...thanks again! Hopefully this summer I will be able to just get my 287 running so I can play around with the car before getting down to the nitty gritty and removing everything.

Edward...Is that on a canadian pontiac or American pontiac? I ask because the canadian pontiacs are very different and I see that you are from Ontario.

[Bill Eveland]

Too bad your switching brands, a 59-60 389 is a bolt in and could be built to have 350 hp cheaper than your fuel injected 350.

[1955Chieftain]

Bill...where to find one and how dependable are they? I thought of a the ram jet because its just turn the key and go. Don't have to worry about tuning the carb all the time or finding parts for it etc. Also gas mileage. 389 is like 9mpg aint it? haha. Just seems silly to me to get a 389 and then spend 2,000 to have a place rebuild it, plus the cost of the engine when I could just get a brand new one. I don't know. Keep talking to me though its helping http://forums.performanceyears.com/groupee_common/emoticons/icon_smile.gif

[Bill Eveland]

If you would even think of doing the 389, make sure you have a good trans, hydramatics can get rather expensive to rebuild, than you have to find someone who can do it correctly.
Someone here on this board could find one or have a 389 for sale.
With the hydramatic 4 speed, probaly closer to 15 or 18 mpg. Depending how heavy your right foot is.
I probaly spent over $2k on my engine, you could find one of the Pontiac vendors that post here for a quote for a complete rebuilt.
"Turnkey and go" how much is that for a complete engine plus fuel injection? Plus trans and rear end. They have fuel injection for Pontiacs now too. If you want to put a Chevy in fine, but fuel injection for anything is expensive. All i'm saying is for 350hp a 389 would be cheaper to build. Plus Pontiacs have way more torque at low rpm than a sbc.
I bored my 389 out to a standard bore 400 , fitted 400 pistons and have the big valve heads. For a low compression 400 you could get some 71-newer heads that would keep your compression down low.

[1955Chieftain]

Bill...these Pontiac Vendors your talking about, are they basically engine shops or..? What kind of mileage on your 389? And are you the same guy that had lots of problems installing the motor. I remember someone talking about installing a newer 389 like past 62 where it was a pain in the ass. What years are direct replacements isn't it 59-62? Also if my trans isn't good what trans should I go with for a 389?

Why don't you just ship me your engine and trans and we'll call it a day. http://forums.performanceyears.com/groupee_common/emoticons/icon_biggrin.gif

[Bill Eveland]

Why don't you just send me a check and we'll call it a day http://forums.performanceyears.com/groupee_common/emoticons/icon_smile.gif.
55-60 bellhousing same, 61-64, than 65 and up.
389 59-66, but if the old trans doesn't work out, for a little more money could go with a newer 400 or 455. Or if you really wanted a stump puller how about a 500cid Cadillac http://forums.performanceyears.com/groupee_common/emoticons/icon_eek.gif.
Or you could put in your 350 f/i engine.
My engine isn't set up for fuel economy, probaly 10mpg at best.
I don't know about lots of problems, just took awile beteween the available time I had to build the mounts.
As far as the vendors , either Pontiac Dude ,Jim Butler, Spotts performance etc. There are alot more but your better off going with at least someone that knows Pontiacs. These are machine shops that specialize in Pontiacs for street/strip or stock engines.

[1955Chieftain]

Why don't you just send me a check and we'll call it a day .

-Did you redo the motor yourself or send it out? If so where? And if you don’t mind, how much?

55-60 bellhousing same, 61-64, than 65 and up.

-My engine knowledge is extremely limited, whats a bell housing? Does this mean only 55-60 engines are bolt in because your next thing about 389 being 59-66 is confusing. Does that mean that up till a 66 will drop right in?

389 59-66, but if the old trans doesn't work out, for a little more money could go with a newer 400 or 455. Or if you really wanted a stump puller how about a 500cid Cadillac .

-newer 400 or 455 is that a brand new trans or just out of a 60s-70s car? Would any newer trans mount up without too much modifications? Wouldn’t a 400/455 shoot the mileage down even more? I’d like a nice driver and not a strip car.

Or you could put in your 350 f/i engine.
My engine isn't set up for fuel economy, probaly 10mpg at best.
I don't know about lots of problems, just took awile beteween the available time I had to build the mounts.
As far as the vendors , either Pontiac Dude ,Jim Butler, Spotts performance etc. There are alot more but your better off going with at least someone that knows Pontiacs. These are machine shops that specialize in Pontiacs for street/strip or stock engines.

-I heard good things about Jim Butler. I emailed him awhile ago but he had no 389s in stock. I could always provide him with one though I think. I’m pretty sure he would have to see the engine though before giving a price. Since I’m not close to him don’t know if this would work due to shipping costs etc if I don’t want to go with him after he gives price.

[Bill Eveland]

The bellhousing is the part of the trans that attaches to the engine, 59-66 389 means those are the years of the 389 , they won't interchange because of the bellhousing bolt pattern differance.
400-455 are larger size Pontiac engines available.
I sent the engine to a local machine shop dissassembled , new pistons, crank machineded, balanced rotating assembly, etc. had over $2k.
Not to be offensive but why not get the car running/driving condition and drive it to see what else the car needs and do some more investigation into what you really want to do before you spend lots of $$$. Make sure its something to want to put alot of money into, since it sounds like you'll have to have somebody else do quite a bit of the work. You may be suprised what the 287 can do if all you want is a cruiser I would leave it alone for now, and besides any time its at the shop you won't be able to enjoy it.

[1955Chieftain]

Oh I plan on fixing up the orginal motor first to play around in it and see for myself. I said that earlier in one of my posts. I'm just thinking about the future as well. Can't hurt to ask questions and know now rather than later.

If I do go with a 59-60 389 what trans work with this without changing the driveshaft?

[carzan]

Mine is an American Pontiac , a Star Chief.

[Bill Eveland]

The trans in the car will work with the 59-60 389.

[1955Chieftain]

Yeah I know the hydromatic thats in there now will work with the 59-60 389 but you mentioned that if it needed rebuilding it could get very expensive. If the hydromatic needs rebuilding or is just caput, what other trans can I use with the 59-60 389 where I don't have to change the drift shaft etc?

[Bill Eveland]

Nothing else will work, if the trans isnt want you want to put money into , than th350, 400 for Pontiac or 700r4 for a Chevy, or with adapter plate the 700r4 will fit 65 and newer Pontiac engines. Or 200r4 for Pontiac , but that isn't a very heavy duty trans.
That 59-60 389 would only be best with your hydramatic.
$1000 ? for the trans rebuild , you would have to check around.
As fas as using the 59-60 block for the front mounting, there are some places that sell adapters to use the 65 and up transmissions, but the kits themselves are $600. And you would still need to have the driveshaft done.

[1955Chieftain]

Heres what I'd be worried about. If I bought a 59-60 389, got it rebuilt and installed and then got my hydramatic rebuilt etc, if I ever run into tranny problems then I'm screwed with the 389 right? Because no other tranny will work with it.

[Bill Eveland]

Pretty much, unless you wanted to pay $600 for the trans adapter kit.

[1955Chieftain]

Well guess I'll get the orginal motor up and running and play with that and continue thinking about what I'm gonna do. I'll probably end up with SBC just because it could be cheaper in the long run.

[Tempest69]

where are you from? i would be more than happy to take that 287 off your hands (if your close by) and put it into a 55 pontiac of my own some day .

[1955Chieftain]

I'm in Maryland but I wouldn't be selling it any time soon. Sorry to disappoint.

[Tempest69]

hmm , thats cool. i cant wait to find my own 55 again someday. my father bought one when i was 10 as a dad/son project but sold it when i was 14 for my '69. i want to do up a 287 like ive seen before with EFI, so if you ever do, ill fork over a small chunk to own it.

[1955Chieftain]

My father brought this for the same reason, a father son project. He then decided he couldn't afford it so sold it to me. I wanted to keep it in the family and learn how to do everything.

[Tempest69]

i kicked my dad off my projects, he gets annoying. never lets me do anything. he'll crap his pant when he comes and see's ive seperated body and frame one day and stripped it, instead of just cutting off whats rusted and replacing it. wants me to do it his way and im not. i want a full body redo and EFI, six gears and one badace suspension setup.

what have you got done so far or you just looking at setups?i dont really ever support corporate power in a tin injun. I still wish you luck!

oh btw, if you use a SBC you might consider using the old shortsnout waterpump. theres a waterpump change somewhere in the 60's and ive seen late model SBC swaps into other 50's cars and they always hit the radiators to much to work.

[Bad Karma]

Speaking as someone who Has had the same car with a Pontiac Ram air III engine and a Built SBC engine I am Going back to pontiac!

There is no comparsion. An EFI motor is Far from Bolt in Turn Key. A Lap top is most likely needed To tune the Injectors Pulse width and Duration. There is Alot of Tuning involved and More Wiring.

Yes EFI is Nice But Honestly I strongly suggest
Putting in a Stroked 389 or 400. Im sure your car is heavy The torque will be appreciated Very much when You finally get it on the road.
Someone else posted in this board a company who
Builds up and modify the 200r4 and 700r4 Trannys to handle Pontiac power and torque.
Going with a Highway gear and Overdrive will bring back some of the Mileage you crave. The low end Grunt will Keep the car feeling good even with a 3.07 gear or 3.23.

you can build an Awsome street stroker that doesnt have to rev to the moon to make respectable Power under 5500 rpm. I have been there and Let me tell you SBC unless its a SPecialty 427 SBC cant ever compare to a Nice Poncho motor.

Now I dont know but I have heard about a tranny from the early 60's called a TH 375. I dont know if that will bolt up to your original motor but I hope it helps in someway. SInce there isnt much needed to convert them to a TH 400 while rebuilding them.

THE vendors Like P dude and Butler Can build you a "turn key carb motor" that you literally install and Drive away. I know atleast one of them does it. It will also cost about the same as the Ram jet 350 that wont be "plug and play".


If I was you and had the means to do it here is a short plan of my ideal build up for a street car ingeneral.

Stroked 400 60's to 70 Block mated to a TH700R4 Built right with lock up converter for extra Highway mileage. If I got real Crazy I would add a gear vendors over drive to get even more gears and better economy.3.23 to 3.55 gears.
Id go with a Hydraulic roller cam for the most power without constant lash adjustments. I would install a Digital Multispark Box like an ACCEL HI-6 or MSD. Upgrade the Tranny and engine cooling system for security.

Ok if you went with this it would be easier to replace parts and keep the Old engine and Tranny IF NUMBERS MATCHING on a Palet in Garage for when you sell car.

Good luck hope it helps. I got the lemans with a SBC for cheap But after a few years of running it I can say SBC isnt enough for a Pontiac IMO.

[Jack Gifford]

That's a big thumbs-up on staying with Pontiac torque!