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
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
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 /
firstname.lastname@example.org (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.
If you're using it in a stock application, it's a wrong move for a lot of
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...
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.
email@example.comVGrrVv (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.
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.
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.
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
The Vampire, "Muffin Man"
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.
It's all about getting air and fuel in, burning it, harnessing
it and getting it out while wasting the least amount of energy
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
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.
firstname.lastname@example.orgVGrrVv (The Vampire Muffin Man) wrote in message
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.
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