Pontiac 1980 HEI


Old 02-08-03, 05:10 PM
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Smile Pontiac 1980 HEI

1980 Pontiac Bonneville
4 Dr 350 TH
4.3 L V-8

I have a new HEI W/vac
For any Small block Chevy.

The Chevy HEI mounts on the right side of cam.

The Pontiac HEI mounts on the left side of the cam.

Do both GM products, use the same HEI model with a different drive gear?

Can I replace the Chevy gear, with a new Pontiac gear, & use it on the Bonnevilles 265 CI V-8?

Thanks for any help you can offer.

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Old 02-08-03, 05:59 PM
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they are completly different distributers most pontiac distributers turn in opposite directions so even if you changed the gear and tried to make it work the vacum advance would actually retard the timing instead of advancing it, and im not sure if there is any other differences or not.
Old 02-08-03, 06:38 PM
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Smile I C

Thanks Bejay,

Of course it would So I need to find an HEI 1980 and back, for a 265 or 301 HEI W/vac.

I'll look at the Iwanna auto parts section tonight, & find one for $25.00 and rebuild it.
Thanks for your quick answer

Old 02-09-03, 07:57 AM
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Different as BeJay said.

Actually, your car should have a TH350C (converter lock up clutch) in that year with the 265 vin S.

Your distributor part # is 1103450 and is good for 1980 Pontiac models with a 4.3 vin S 265 Pontiac V8.

1981 was EST and would be different (no vacuum advance).
Old 02-09-03, 10:35 AM
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Joe Said:
Actually, your car should have a TH350C.

This fine Bonnie had only 2 main problems, when it left it's birth place. Instead of a TH 350 it came with a 300 that lasted for 65,000 miles. So it was replaced with a TH 350 + 3 drain plug fitted Torque Converter & Trans cooler.

Check Engine light & all the nonsense that came with that in 1981, that was absent, in 1980 was the other big problem. I love Computers, only not in my ride.

We have a NOS non Computerized Carb & will match that with the 1980 HEI with vac advance. Now we will have total engine control, but I will have to put a sticky up on the dash too *Check Engine * just kidding, I never want to see that Idiot light again.

Like the Cast iron Master Cylinder of 1980, I used to replace the plastic & Alluminum Master Cly that was pitted at only 50,000 miles on my 1981 C/10.

In the Chevy P/U & the Bonneville 1981 was a very bad year, Thank God GM stays with good parts, that will fit both late & newer model cars & trucks. You can retrofit the 81 with 1980 parts.

211,000 miles & hoping for another 100,000 more without being told to do, what comes natural. * Check Engine *

I just forgot to factor in the distributors reverse rotation into, vac plate rotation. I found a like new GM HEI for $20.00 yesterday off a 1981 265 CI. The guy replaced the HEI with an accel Blue Printed HEI with remote Coil, leaving a perfect 1980 GM HEI stored in the Accel box all cleaned & ready to go.

What do you think, will this Bonnie go for 300,000? Comp specs: Lo 147 psi HI 160 psi .

Thanks for joging my memory bejay, I have been in the Garden, Shooting guns, & living in the outdoors, driving Clasic Chevy's & forgot about the backwards turning Distributor, of the Metric Pontiac LOL

A really fine car with out HAL in control. Well in a few days it will be a 1980 Bonnie, ready for it's 3rd 100,000 mile run

Thanks all
Old 02-09-03, 02:10 PM
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The 300 trans was not used in 1980 with the 265 V8 vin S. Only a 350C (option code MV4) or a 250 (option code M31).

In 1981, the trannies used were: TH200 (MV9). Possibly another tranny, but the book only shows one.

The only 300 series I know of is a Super Turbine 300 which was like a Powerglide and was 2 speed. That was the 1960s.

The best distributor is plain stock GM HEI. This will run great in mostly anything unless you are running some high end stuff.

I'm not sure if you are saying you have a 1980 or 1981. 1981 was computer controlled, 1980 was not. Yes, you can put a 1980 version in place of a 1981, but the fact is that eliminating the computer gives you zero benefit and most are removed due to not understanding how they work .

Case in point: My uncle had a 1981 Cadillac 4-6-8 that ran flawlessly for 150,000 miles as designed. I saw the car in 1988, it was absolutely mint.

This Bonneville is a car you just get in, drive and maintain. It won't win any races, but it will run well for many years
Old 02-09-03, 05:02 PM
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Smile A change of choices for a DIYer.

The TH 200 was replaced with a TH 350 & that was 141,000 miles ago. Although the 1965 Buick Special, had the ST 300 that went 200,000 before it's untimely accident, that bent the frame..

However the Trans has nothing to do with replacing both the Carb & HEI with the ones, that will now be controled by engine vaccum. The orig, E2ME has a well worn throttle shaft after 200,000 miles & I decided, not to go back with the same lack of choices that came with this 1981. I just prefer it that way, much like, I still use the same Points type Distributors, in the 69, 70 & 72 Chevrolets, 2 C/10s & and 1 Impala.

I think it was a good move ( Computerized ) at that time by GM as many of the Mechanics who understood how to setup and tune a Carburator. Were retiring & many of the new Techs, never learned how to tune Carburators in school, due to the move to fuel injection.

As you noted the 4.3 L was not a track burner, so many of the aftermarket parts makers, never bothered with the 4.3 L. Delco is in the HEI now, and that is all this little Small block needs to work with, the Stock HEI.

All that is changing, is Now both the Carb & HEI will be setup and adjusted by the same methods that were used before GM installed a Computer to make, electronic choices on the fly. As the engines sensors report their findings to a chip set, they try a series of presets, until everyone down line was happy.

I believe both the Bonnie & I will be much happier having the options now, to make those choices that the engine needs to run it's best.

That's all I am doing, just drifted for a moment on the Backwards rotation, & the result of the vac advance being pulled away from the rotation, instead of into it for advance to occur.

Enjoy it while you are young, it doesen't last forever LOL

Old 02-09-03, 05:46 PM
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It's a plan that works for you so go for it

BTW: There is no Pontiac small or big block. Externally, the 265 vin S in your car is identical to a 455 vin W used in a 1976 Trans Am or other Pontiac .

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