Greetings:I'm thinking about installing a 389 in a '56 Pontiac wagon that came with a 287. I have searched the archives but haven't found anything on this subject. I'm reaching out for some help on this. Are the blocks the same size? original motor mounts work? I'm sure someone on here has done this before, so there's no sense in reinventing the wheel. Any help on the do's and don'ts would be greatly appreciated. Thanks, CBN.
As long as it's a '59-'60 389, it's pretty much a bolt-in. '61 saw changes to the bell housing pattern.
I think its a later 60's engine,I'll look into that.I haven't bought it yet,just waiting to see how it would all go together. Tman, I don't know Rocky. Any help on that ? Thanks, CBN
389s were made from '59-'66. As I said, a '61 or newer engine won't match up to your stock hydramatic. Also, your stock front engine mount won't work on the later engines; the timing cover also changed in '61.
OK more info: It is now connected to a chev bellhousing and in a truck, has 13" clutch installed.I would go a auto trans myself. LH head # 531395 RH head # 531895, block casting #532000 GM2.
Sounds like a '59 engine. There should be date codes on the heads; for instance, C 4 9 would mean March 4, 1959. The bell housing sounds like it's from a mid '50s GMC truck, as some of them came through powered by Pontiac V8s.
532000 is a 59 389. You can get a trans adapter from Wilcap or Bentsens if you want a newer style trans. Otherwise if your using the dual range 55 trans, transfer over the 287 flywheel to the 389. The dual range torus uses alot more than newer style trans. And seal up the flywheel to the crank with some anarobic sealer. Trans places like Fatsco will have the torus to flywheel gasket.
First, the 56 Pontiacs had 316 engines, not 287 (55 Pontiac only). Second, 56 was a changeover year for the automatic transmissions. If you have a Park position, it will be the Jetaway dual coupling type automatic, which should be fine with a 59 389. But if it does not have a Park position, then you have the earlier dual range hydramatic. If this is the case, then you will need to install a pilot bushing in the 59 389 crankshaft, as the earlier hydramatic has a pilot shaft. Jetaways do not. As far as attaching the 316 flywheel (if you have the earlier transmission), I would purchase the flywheel to torus cover gasket from BEST. You can find them on EBAY. Along with the flywheel to torus cover gasket, BEST supplies a flywheel to crankshaft gasket. Using the anarobic gasket sealer itself is not a guarantee of no leaks. I use the gasket, along with PLIOBOND 30 on both gasket and bolt threads on my cars.
Using a '58 front engine cover should fix the engine mount question,.... Sounds like a great poject. 4TRUK
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