Changing from TPI to Carb

I would like to know if I purchase a used 87 350 TPI engine and have it rebuilt for a carb engine would I need to change out the heads or just the intake manifold? And if I need to change the heads, could I
use the ones from my 305?
Thanks,
Kevin
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I believe that 87 up small chevies with 'cast iron' heads changed the intake bolt pattern, I think it's something like the center two bolts on each side changed to 73 degree angle. Aluminum heads retained the traditional bolt pattern, which is 90 degrees from the flange on all. Edelbrock sells both style intakes. For an 87 model year Block, you could slap on the heads from anything that was older(305 heads will suck for power), and 'some newer ones' as well. If your not aware, and you like power -one of the best bang for the buck heads for small chevy are the factory 'L31 Vortecs'. However the vortecs require a Vortec specific intake, also avail from Edelbrock, vortec intake gaskets, centerbolt valve covers(you prob have now), and self aligning rocker arms. The 'Factory' Vortecs are limited in how much Camshaft lift you can have about .440-.450 @ the valve. If going the Vortec route I would opt for special machined Vortecs for high lift cams avail from Scoggin Dickey. http://www.sdpc2000.com /

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Why?? I'm a little biased as I'm certainly a huge fan of fuel injection. The drivability is generally better. The fuel economy is slightly better. And they just look good.
Forget the 305 heads.
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snipped-for-privacy@aol.com (Big Dav160) wrote in message

Thanks everyone for the advise but here are the reasons for my choice in a TPI 350 change over to a Carb.
1. I feel troubleshooting a carb problem is much simpler for someone like myself from Old School engines. TPI and Throttle Body setups are complicated to troubleshoot. And that coming from someone who does complicate computer networks for a living.
2. Here is the kicker I live in a state that still requires emission testing. My son and I are rebuilding this 87 Pont Firebird as a father son project and I have to keep the engine in standard OEM condition to pass a test. But I did change out a GTA TPI350 years ago but didn't remember if I switched over the heads.
Thanks again,
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If you're using it in a stock application, it's a wrong move for a lot of reasons:
1) FI is inherently simpler than carburetion, as much as people will claim the contrary. Most claim that out of ignorance---time to step up to the times.
2) A 305 as TPI will perform better, run smoother and get better fuel mileage than any other carbureted 305 of the same vintage.
3) Here is the kicker I live in a state that still requires emission

---With that being said, you answered your own question, it's "illegal" to do what you are doing. You're going to have to find all of the same OEM 305 carburetor emission and control parts for that year. It will cost you more to cobble that together than to fix the original setup.
A computer controlled Quadrajet is just as complex as a FI TPI setup, so you aren't gaining anything in simplicity by going to a C3 Q-jet.
Keep it stock, leave it alone and just fix it as is. Ten times better off. Joe--ASE Certified Parts Specialist & 10th Ann.Club Tech Director '80 Carousel Red Turbo T/A, 26k orig. '79 "Y89" 400/4 speed 10th Ann. T/A, 57k orig '84 Olds 88 Royale Bgm 2 dr, 307 "Rocket" (lol), 141k and still going.... '80 T/A project car...
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If you want the engine to ake any power above 4700 rpm just scrap the FI system. A properly sized and tuned carb and intake still make slightly more peak HP than any FI system. As far as the Tuned port systems goes, its one of my favorites for street use for looks alone. It certianly lacks performance and its not designed to rev above 5k rpm. You can get a TPI system thats a real street killer for about $1700, but it doesnt use any stock parts. A carb is WAY cheaper.

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Umm... You're full of shit.
The Vampire, "Muffin Man"
--
Do not taunt Happy Fun Car.

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snipped-for-privacy@aol.comvVGrrVv (The Vampire Muffin Man) wrote in message

Ummm you are a completely uninformed asshole..... A GM TPI system, falls FLAT on its face after 4700rpm. A carb will kick the crap out of ANY GM TPI system for peak HP and performance numbers. Most honest race engine builders will tell you that a carb motor will get a higher PEAK HP number than the same engine with a Fuel injection system. I love the TPI set up, but its just eye candy, perfect for a cruiser, but thats it.
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Rommel said that a carb will make more power than any FI system.. I find that hard to believe. I can believe it if we're talking strictly TPI but ANY injection system?
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Uh huh... Gas has a certain amount of energy in it. Burning it can create a force. Creating it quickly is work, which is horsepower. At no point does the method of getting the gas delivered change this.
That said, the TPI doesn't rev. Neither does a 1 barrel slant-6.
Carbs and FI have good and bad points - but neither of them will magically make more power than the other. Period. It's the whole engine that determines power production. The carb/injector is just a delivery method for gasoline.
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Really? So head porting is just a big scam? Higher Intake velocity for carbs and fuel pressure for FI dont affect the atomization of the fuel, there fore creating a more finely atomized mixture leading to more efficient combustion and higher HP and torque? WOW!, better get someone on the phone, the laws of physics just changed!!! A more ignorant statement I'm sure I will never find.
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You seem to be the confused one. If I have one engine that is carbed and one that is FI and they are set up so that the same amount of air/fuel gets into the cylinders, you think what? The bad statement was that a carb can (set up properly) produce more power than *ANY* FI system. I called bullshit. If you can't deal with that, too bad. I'm still scratching my head about the head porting...
The Vampire, "Muffin Man"
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Do not taunt Happy Fun Car.

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Me wrote:

Ok dummy, I'll use smaller words for you. One unit of Gasoline has a certain amount of potentional heat in it. This can be burned and can be harnessed to do work. None of this matters in what kind of fuel delivery system you use.
This proves that F.I = Carb for theoretical horsepower production. Or the other way around. It matters not how the fuel gets there, as long as it gets burnt the same.
THEORETICAL. The comment was that carbs are better for HP than FI. Period. That statement is BULLSHIT. A properly set up tunnel ram that revs to 9 grand will mop the floor with a TPI, but that's not a fair fight. Which one will start in -10 degree weather? I have yet to see too many Vipers (or 4th Gen F-bods) converted back to carbs for more power.
idiot.
It's all about getting air and fuel in, burning it, harnessing it and getting it out while wasting the least amount of energy doing that.
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Atomization is also important.

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Funny... I wasn't being an asshole. If I was, I would have made completely out-the-ass personal insults.

I'm sure that's true.

That would depend on the carb. and intake, I'd suspect. Peak #s don't mean shit, though.

I think you're missing the big picture and making too many general statements and in the wrong places.
The Vampire, "Muffin Man"
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Do not taunt Happy Fun Car.

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Boy I touched a nerve on this thread. Wasn't looking for the best of the best just a fun father and son project in an emmission controled state. I have in the past taken a 305 Carb out of an 85 Pont Firebird. Purchased a 350 TPI out of a later model GTA. Had the engine rebuilt and added the 350 carb heads. Then I replace everything else back to the original 305 setup (i.e. AC, Alternator, and other). It ran great and past the emissions testing. Yes I kept all the emission stuff. After a year or two the only thing that I hated was that I had to pull the Edlerbrok headers and put the stock ones back on. That is when I sold it. This state goes back to 84 for testing.
As far as "IILEGAL" modifications as stated herein, I have taken every step to ensure that it stays legal. Years ago I could get my garage guy to replace a 305 for a 350, but like the guy said it is Illegal to replace a 305 for 350. Go fugure it's your car and as long as it passes the emissions test no more is said about it.
Hopefully this thread dies, because it is becoming less helpful and more combative for the Carb vs TPI/FI folks.
Kevin
snipped-for-privacy@aol.comvVGrrVv (The Vampire Muffin Man) wrote in message

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Personally, I have no stake in TPI vs. carb. I don't really in carb. vs. any FI either, even though I plan on going with an aftermarket TBI on my '74. I'm going to make sure I have the carb. setup, in tact, on the side, of course... I just think the statements made were foolish. I didn't mean for the person I was replying to, or anyone else, to infer that I was insulting their intelligence or anything of the like. I'm just thinking that you'd be better off retaining the TPI and keeping the car stock as possible to keep the emissions happy and that it won't cost you as much as setting up the car for a carb. If it was a TBI or if you were significantly modifying the engine, then I'd have to think about it. But as is, the stock cam is going to be matched to the intake setup, so swapping would mean you'd want to go with a new cam as well, to make the most of it, and on down the line... Basically, if you're going to swap, you might just want to build the engine from the bottom up to make the most of it. Considering it's a father/son thing, I'd go ahead with keeping the TPI, though. Good learning experience with the modern-tech. to make him feel at home... If you want him learning old school stuff, buy an older car later (maybe for college grad, or something) and go ground up and big, bad, real muscle under hood. Anyway, that's my $0.02.

The Vampire, "Muffin Man"
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Do not taunt Happy Fun Car.

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