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Hi I was wondering if I could get some knowledge from someone on an engine rebuild. I'm picking up a 60s Pontiac 389 that a friend gave to me and he said its froze. I want to rebuild it and try for somewhere around 400hp. Any suggestions on where to look for a good rebuild kit and possibly some pointers from someone who may have exp. with these engines would be much appreciated. Thanx
 

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Hi I was wondering if I could get some knowledge from someone on an engine rebuild. I'm picking up a 60s Pontiac 389 that a friend gave to me and he said its froze. I want to rebuild it and try for somewhere around 400hp. Any suggestions on where to look for a good rebuild kit and possibly some pointers from someone who may have exp. with these engines would be much appreciated. Thanx
There are quite a few threads here on the Pontiac engine. Also see the Crankshaft Coalition wiki pages Pontiac info and sites and Pontiac V8 engine.

Be aware that blocks older than around '64 are more difficult to use in newer vehicles because of the motor and starter mounts.
 

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What year 389? It makes a difference in how to approach it. '64-older are less desirable heads but good blocks. Later heads DO "fit". 400 parts also fit.

Most important, define a goal for performance/usage. Build accordingly. It's NOT "a Chevy" so most of the "standard" hot-rod modifications made to Chevys don't apply. What car?

Jim Hand's book "How to Build Max-performance Pontiac V8s" published by SA Designs is the most current study of the ol' *****. It's now 8 years old, sio some of the info is obsolete. The "history", "rationale" and short block sections are ALWAYS "current"... :)-

Jim
 

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Discussion Starter · #5 ·
Thanks but I probably jumped the gun a little asking questions when I'm not sure what year it is. Once I get the engine I'll find out for sure what year? Then I'll get back to u. Thanks for that info though
 

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Discussion Starter · #7 ·
I don't have anything yet but I'm shooting for a 70s trans am. This will be the first engIne rebuild I've done and I'm pretty mechanically inclined and grew up around cars and have a friend that is gonna help me but I'd like to go into this with some of my own knowledge. The 389 is a single carb 2 barrel wich I believe stock puts out 280 or 290 hP. Do u think this is a possibility or a waste of time?? I figured since I got the engine free it was the right price and I've been wanting to do this for a long time.
 

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The motor mounts wont bolt on as there are no bolt bosses on the 389 for an F Body car.
Also the 64 and earlier 389 had no bolt bosses on the block for a starter either.
You need to get a 70 or later block as they have 5 bolt bosses for motor mounts. Even then some block may not have the bosses drilled and tapped, but that isnt hard to do when you are building the engine.
For a good street engine the 455 is a good choice. No replacement for displacement.
Before you buy ANY block, do some research and ask questions.
Dont get that 1963 389 you are talking about, unless you want loads of dissapointment.:nono::(
 

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Discussion Starter · #10 ·
Haha! It already sounds disappointing. Even if I decide to put it in a goat, do u think I can achieve the horse power I'm lookin for or is it basically a nastalgic boat anchor?
 

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Well ,it will make 400 horses pretty easy.But it wont be correct for a GTO .
The 63 back 389 used a bell housing mounted starter , making it a bit harder to run a decent trans.
It would be OK for an older poncho like 63 and back.
I would look around, shop around, ask questions.
You have done the first thing you should do when pursuing a build. You have decided to build a street machine/daily car, with around 400 horses. Totally do-able, and sure to be loads of fun.
So , for a street machine, you need to get a car. That will be your next choice.THEN look for an engine to build, as I said some wont bolt in or work correctly.
A 400 is an awesome engine, a 389 is also good but remember what I said about motor mount bosses(bolt holes)
You wont find a 389 with the correct bolt bosses for an F body (firebird-T/A ) so dont even bother. And the 400 was built in 1967-up. But the 400 wont have the extra bolt bosses for an F body either, unless you get a 70 or later block. It pays to shop, but get schooled a little first.
Do some looking at block casting numbers and date codes and such.
http//:Wallace Racing-Drag Racing Pontiac powered Firebirds,Trans Ams and Dragsters is a good place to start with some basic info. They have a lot of tech info that you will want to learn about.Like how to ID a block from the casting number, where to look, how to date it, by date code and how to decipher... lotys of good reading over there.
I will post a few others for you too. Later
 

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Discussion Starter · #13 ·
Hey thanks very much for the info I'm sure I'm in for a learning experience but I am committed to the 389 for as it was free and I want to bring it back to life for my first rebuild and hopefully find something reasonable to put it in. My friend is dropping it off to me this weekend and when I get the numbers off it and learn a little more about the motor I'll certainly keep u posted for some pointers. Thanks again latech
 

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Ames Performance and Performance Years both offer the mounting "adapters" needed to install the earlier blocks in later cars. Not a cheesy "fix", either.

For all intents and purposes, 389 has exactly the same potential as 400. The only parametric difference is the bore size, .060" smaller. Cranks interchange. Using 400 heads from the late '60s makes 400 HP a slam-dunk. Good cam, induction and exhaust and you're "there".

What Lynn (LATECH) says about the starter mounting is correct. All '64 GTOs had the "block mount", but most of the "big cars" still had the bell-housing mount. NO problem is "insurmountable", just impractical.

Jim
 

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These guys know more about 389's than I do. I used to fool around a lot with the 400's back in the 70 and early 80's with great sucess. But I can tell you that Pontiacs were known to have weak connecting rods, and it was worth every penny to have the cranks cross drilled and use full groove main bearings. Considering gas today I am thinking you would be building a pump gas motor ? If so keep the compression no more than 10:0 or maybe 10:5 to 1. Lunati used to make some cams that worked extremely well in the 400's. Headers were always a pain in the keester because of the angle of the exhaust manifold bolts, and then you get into the separated Ram Air heads. 400 HP is easily obtainable thou. With a Pontiac you just have to come up with a plan and stick to it. They are not as diverse as SBC, BBC, and some others. You have to know exactly what heads your going to use B4 you buy pistons, and cam, etc. Just make sure you use all forged & balanced rotating assy for the lower end AFTER you decide what heads your going to use. If your choice of heads doesn't already have screw in rocker studs pay the price and get it done ! And for Gods sake don't use the tri power...LOL They were nothing but a fire hazard even back then. I always had great luck with Pontiac motors. But it came with big disappointments at times as well. They are good motors to build as long as you learn thier weakness's first. Bad OEM connecting rods, usually bad OEM cranks, head to piston issues at times, press in rocker studs mostly, and if you can use the Ram Air seprate exhaust port heads opposed to the more conventional 2 inner exhaust side by side ports. Just make sure you can obtain a car that this 389 will work in....LOL Shame to build it and have nothing to put it in....LOL
 

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The adapters make it so the block will fit, no problem. You're going to bneed the later heads for brackets to all "line up" correctly. There's one bolt "hole" missing in the 389 heads.

Ed, where did you ever "hear" Pontiacs have bad cranks? Simply not so. In fact, the crank is the strongest part of the Pontiac. The block is the "weak link" once the cast rods are disposed of. I don't "fool" with Pontiacs. I build them at the highest level (one 505 has produced over 2,600 HP).

Virtually everything you speak of is obsolete for 20 years now. With the advent of NMCA and muscle car "racing", developement of the ol' ***** has resumed, and they're "back" with a vengance. At the last "Super Chevy" show we attended, the quickest GM-powered car was a Pontiac, not a Chevy. Dirty Bird had them ALL "covered". One of the exhibition cars was a ProMod with an 800" Chevy in it, and a BIG fogger system. We had him by .2 in the 1/8th. There WERE two ProMods with "Brad" motors. They had US covered by about .15. In the competition, Frank Gostalya's GrandAm (540 CID, single 4-bbl., gasoline, no adders) went 7.50s all day,very near 200. The only two Chevys that were quicker had 738 CID and big foggers. They ran 7.40s. Yes, things have changed a LOT
 

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The adapters make it so the block will fit, no problem. You're going to need the later heads for brackets to all "line up" correctly. There's one bolt "hole" missing in the 389 heads.

Ed, where did you ever "hear" Pontiacs have bad cranks? Simply not so. In fact, the crank is the strongest part of the Pontiac. The block is the "weak link" once the cast rods are disposed of. Vinny Meyeda of SoCal, runs a 6.90s F/C with a 406 CID Pontiac with a factory nodular crank, spinning to 8,800 every pass. I don't "fool" with Pontiacs. I build them at the highest level (one 505 has produced over 2,600 HP). The 475 in Dirty Bird made 40 passes, shifting @ 9,200, without a single bearing or piston issue. The rod maker says that's all the rods are good for over 2,000 HP. And the same 8 pistons that were in it on the first pass, were in it on the 40th. How many blown/alcohol hemis and BBCs can "say" that, while setting new ET records at the same time? DB was the quickest Pontiac-powered car in the world for nearly 2 years. Still IS the quickest Pontiac "funny", and hasn't been down the track in over a year. The KRE crowd is encroaching, though. Bill Mellot's F/C went a 6.50 at Norwalk earlier this month. We're gonna have to drag it back out and put a "tune" on it, to move the "bar" out further. We'll see what Dave (owner) has in mind. "Catching" the Butler ProMod is going to be a chore, let me tell you! (6.27 @ 22, IIRC)

Virtually everything you speak of is obsolete for some 20 years now. With the advent of NMCA and muscle car "racing", developement of the ol' ***** has resumed, and they're "back" with a vengance. Afterall, can't have muscle car races without GTOs, and can't put Chevy motors in GTOs "just because", so the money flowed and the new parts came forth. Today we have a selection of blocks, heads, cranks, and everything else, that rivals that of BBF and MOPAR. At the last "Super Chevy" show we attended at VMP (2010), the quickest GM-powered car was a Pontiac (engine), not a Chevy. Dirty Bird had them ALL "covered". One of the exhibition cars was a ProMod with an 800" Chevy in it, and a BIG fogger system. We had him by .2 in the 1/8th. There WERE two ProMods with "Brad" motors. They had US covered by about .15. In the competition, Frank Gostalya's GrandAm (540 CID, single 4-bbl., gasoline, no adders) went 7.50s all day,very near 200. The only two Chevys that were quicker had 738 CID and big foggers. They ran 7.40s. Yes, things have changed a LOT coming out of Oakland County... Circle the wagons, boys, it's an ***** ATTACK!!!

PAX

Jim
 

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if you have the room, there's no reason NOT to get a free engine. You'll find a use for it eventually, weather its to put in your car, or maybe horse-trade for something better suited to your application.

Best thing for you to do is follow most of whats been said; ditch the factory rods and use a pair of later heads with the correct chambers for your build. We build stickshift transmissions and the only issue I ever see with a pontiac build aside from the 'speedometer cable goes in the wrong side of the trans' is that SOME people seem to have had an issue with using a crank from an automatic trans equipped car in a motor destined for a manual gearbox. Sometimes the pilot hole in the crank isn't machined properly for the pilot bearing/bushing for the manual trans. This can also crop up in early chevys (283s and 265s) and occasionally we see offshore stroker cranks with a looser bushing/bearing fit than we'd like to see. So make sure you get the correct dimensions and check your pilot hole. It may be easier to use the automatic if the crank needs to be machined to get the manual trans in the equation
 

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if you have the room, there's no reason NOT to get a free engine. You'll find a use for it eventually, weather its to put in your car, or maybe horse-trade for something better suited to your application.

Best thing for you to do is follow most of whats been said; ditch the factory rods and use a pair of later heads with the correct chambers for your build. We build stickshift transmissions and the only issue I ever see with a pontiac build aside from the 'speedometer cable goes in the wrong side of the trans' is that SOME people seem to have had an issue with using a crank from an automatic trans equipped car in a motor destined for a manual gearbox. Sometimes the pilot hole in the crank isn't machined properly for the pilot bearing/bushing for the manual trans. This can also crop up in early chevys (283s and 265s) and occasionally we see offshore stroker cranks with a looser bushing/bearing fit than we'd like to see. So make sure you get the correct dimensions and check your pilot hole. It may be easier to use the automatic if the crank needs to be machined to get the manual trans in the equation
The cranks on early (pre-'64) engines aren't correct as-is for TH-type torque converters, either. They need to be machined to accept the TC hub.

I also tend to agree- a free engine is bound to be worth something- if not now, then down the road.
 
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