Alright Guys- Here is what I'm looking at the 389 in my 59 Pontiac Starchief is getting tired defiantly needs a head gasket and probably a total rebuild to do it right as of now the pocket book cant afford it. what i have found is a 72-74 455 (engine casting number 485428) with a turbo 400 bolted to it Before i go down this whole adventure and run in to a ton of issues a friend of mine who has a restoration shop and is a big gto guy thinks this swap will go fairly well. but i would like some more opinions. just remember im 25 dont know everything but trying to learn. sorry if i posted this in the wrong spot... im not a regular around here anymore
I'm with you as a 20-something that's learning and it sounds like you have a good resource in your buddy. I'd always condone swapping a bigger badder engine but you also have the benefit of going to a more common transmission. Also cool that you're keeping it pontiac. Sent from my SM-G930T using The H.A.M.B. mobile app
Should be only a few small issues to easily overcome - accessory brackets in the front of the engine and possibly a drive shaft if you use that turbo 400 as well as exaust . I'm sure the Schmendricks here have more... but they will be small issues.
he is defiantly a good resource but like i said he is a big gto guy have been looking around for information or some one out there that has done something similar before i dive into it myself...
the old man is a welder with an awesome set of tools!!! supposedly all of the stuff that bolts to the front of the motor is all there... and my gto friend said the drive shaft was probably going to be and issue... maybe there is hope for this swap yet!!!
The engines are the same size and weight, but, the mounts are really different. It shouldn't be all that hard to convert the mounts. The trans will need to swapped as well or you run into starter problems trying to use the older transmission, plus it might not like to torque of the 455. Use all the 455 brackets that you can, and clean or replace the radiator. 455 's will run on points or HEI and use the Q-jet thats on the 455. Replace the cam with a Summit Racing 2801 Cam & Lifter kit which is really close to the GTO 4 barrel #068 camshaft. You will have a very nice driving and sounding car with tons of torque off idle. Use the stock torque converted. The length of tailshaft the Turbo 400 has will determine the driveshaft length, nothing to terribly hard about the whole swap. If you really want more power, look for #46 heads off a '74 GTO, they will give about 9.0-1 compression, same with the '77-'79 #6X-8. The 4X heads on the 455 now can be milled for higher compression or you can swap on '73-'74 350-400 4X heads. All the older 72cc heads from '72 and earlier will raise the compression way to high, there are exceptions like the 455 HO heads, but they are getting hard to find. Another really good head is the #96 off the 400's of '71-'72 era. You want high 80's to mid 90's CC chambers for 9.0-1 compression. Even with the stock 8.0-1 compression the 455 has, it will run good and be able to use any gas you run through it. Joe
There will be some other issues ***uming you want to keep the column shift. The indicator for the stock super hydro in the car now is different than that of the turbo 400. Neutral safety switch is also part of the deal. Depending on how far you want to get into this. Not dissing any info you might get here, but Ames Performance forums is all Pontiac. You can probably find just about any answer to any question you might have. Just a suggestion.
alright guy with some more research it sounds like i have been convinced to dive into this project... any advice on what size carb i should run... it has a 4 barrel edlebrock intake on it now...
* edit Are you saying the 455 has an Edelbrock intake, or the 389 does? What heads are on the 455? Use a standard Edelbrock Performer and the Q-jet from the 455, as already stated. The intake from a 72 would be okay, but not from a 73-74 . Significantly different. The cast 67-72 intake will run just as good as the Performer , but it is quite a bit lighter.
Once you change that car over to a 455/ 400, there's no going back . Too much different stuff. I don't see how you'll save much money, going this route anyway. Who said the 389 has a blown head gasket ? Probably should pull the 389 and dis***emble and see what you've got first.
Pontiac parts about the same price for a 326 or 455 and everything in-between, so tear into the 389 and see what it needs. It will cost nothing to tear it apart and look. The 455 needs about 700 to 750 cfm carb, stock Q-jets work really good on them. If you have the stock intake form '73-'74, just plug the EGR ports and run it, they will work just as good as any of the earlier intakes, just a little uglier due to the EGR. I have flow numbers form all the variations of intakes Pontiac used, and all flow really close to the same amount of air.
Wouldn't think you need to rip the 389 apart to determine a bad head gasket. How many miles on the 389? Original or rebuilt? If the 389 heads only had to be redone that's a lot less of a h***le than a whole drivetrain swap (IMO). How is the ****** in the car now....I ***ume it's the hydro. I like that trans but getting one rebuilt can be a problem FYI.
so to try and answer everyone's questions at once here is whats going on... (please im not trying to tick anyone off just stating my facts 1. all the signs point to being a head gasket issue... not going to get into that. 2. im hoping to have the original numbers matching engine and trans rebuilt down the road. (trans needs a rebuild to.) 3. the 455 is supposed to be a good running motor and turbo 400 trans(from a trusted source) 4. the 455 is $800 so im probably going to get it if i put it in there or not finally after talking with some guys on other forms who have done very similar swaps this is very possible without much modification ( and my dad has a metal shop and me being a product engineer we both take pride in being able to put back anything made out of metal back to what it once was...) if it gets to the point where MAJOR modification needs to be done ill surely stop and reevaluate the project. thanks everyone for the advice mike
Regardless of whether you rebuild the 389 or do the 455 swap, there are a couple of books that are required reading for those into performance Pontiacs. (1) Pontiac Performance 1955-1979 by Pete McCarthy (2) Pontiac Engines by Jim Hand (hint - see who posted post #9) There are other good books, but those two are relatively inexpensive and EXCELLENT references. Jon.
You are right the 389 has some awesome power for what it is... even being as tired as it is... Sent from my iPhone using The H.A.M.B. mobile app
LOL I knew everything when I was 25 now I am 64 and am starting to learn. Thing to remember is that the 455 is not going to be a bolt in, it is an engine swap. For your '59 even the later 389-421 is going to be a swap, easier by far then the 455 but will still need some minor things changed around. I personally would not be afraid of any of those I options but I am not as smart as some and not much scares me.
don't get me wrong im 25 and definitely don't know much... by no means i know it is not going to be a bolt in situation... was more just looking at it from the point of if i need to make new motor mounts or if i was going to have to make a whole new ch***is to make this happen...
LOL if you don't want to fab mounts and you look around a little bit you can probably find engine swap mounts that will work. As for new ch***is that is a sort of a new millennium thing. We used to swap one of everything into about one of everything and *** was always just a matter of building mounts. I see people building new transmission humps now too because the one that have isn't quite big enough (yours may be a little tight) on about anything built from '40 up we always just used a big hammer and beat the offending sheet metal. The thing to remember is that it is just a damned old car. Your 455 or another 389 based block (*326, 389,*350, 400, 421) will fit and should be a pretty straight forward install. *I may be wrong about the 326 and 350
i was probably over exaggerating with the new ch***is statement but was trying to get my point across... trust me it will not get to that point... the ****** hump may have a date with a hammer also lol... and like you said ill probably buy motor mounts online somewhere... it sounds like we are on the same page on this... wanna come up to minnesota for a while and help lol...
Love too. I got some friends in twin cities that I have not seen in a minute that probably would mind a visit. When I am looking to do a swap and don't have the time or the inclination I usually try Trans-Dapt. Advance adapters may have something too. Hell you may drop it in there and go hey this fits and not need anything at all, stranger things have happened.
Sounds like you are still short some of the answers you have been looking for. Did you go on the Ames Performance site and join up (no cost to do it)? Damn sure you can get the answers to most of your questions there, like motor mount patterns on the blocks.....old vs later vs both, and which motor mounts are available. You will not have a tunnel issue if you go the 455/turbo 400 route. I have a 60 Ventura Vista and the tunnel on that is slightly smaller than that of the 1959. Turbo 400 fits in the 1960 wo any issues as far as I know. Don't know how you use your car but here's a comparison on initial gear ratios of what you have vs what the turbo 400 will yield. I'm betting you have the standard rear end ratio of 3.08 same as my 1960. With your existing setup the initial gear ratio is 12.23 (3.08 x 3.97 super hydro low gear) compared to 7.64 (3.08 x 2.48 turbo 400 low gear). If you are just a cruzer like me, it really doesn't make any difference since the super hydro shifts to second gear (2.55) at a pretty low speed and is hardly noticeable unless you really get on it.
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