I'm in the process of building an engine for my '84 Firebird. I've been thinking about different methods of intake and it occurred to me that TPI is a thing and it might actually be the best set up for what I'm doing. The question I have, is since mine is an '84 and the wiring harness is completely trashed, generally speaking what am I going to need aside from the unit itself to make it work? I've got an engine wiring harness out of the donor car that the engine came out of, but it was set up for a carburetor.

Now obviously, I would need a fuel pump, a computer of some kind, a new wiring harness, new TV cable and throttle cable, accessory drive, and some other things... but do I need to have the wiring harness from a TPI set up, or is there aftermarket stuff that'll work too?

About my build:

Donor engine and wiring harness is out of an '87 Caprice 9C1.
Block is a 2 bolt main 350 bored 0.030 over with squared decks, pistons sit about 0.023" in the hole, will probably use a 0.028" thickness head gasket by Chevrolet Performance
I'm using the stock 083 heads. I had the machine shop put 2.020" intake and 1.600" exhaust valves in it with LS6 beehive springs and 1.52:1 roller rocker arms on screw-in studs
Pistons are Sealed Power hypereutectic pistons with 6cc four valve relief on stock connecting rods on the stock crank
Camshaft is a Howard's Hydraulic Roller cam: 213/217 duration @0.050 - 0.485/0.495 lift - 114 degree LSA
Exhaust is Flowtech shorty headers going into a Y-Pipe out the back to a 3" Magnaflow exhaust

The whole idea behind the build is something that'll be a nice, reliable daily driver with good idle vacuum and plenty of get up and go off the line. I feel like I could probably get that with the stock cast iron intake manifold and quadrajet from the Caprice, but the TPI set up will give me more at the low-end as well as be more convenient thanks to the fuel injection.

Biggest question is, would it actually be WORTH going from a stock cast iron intake manifold to a TPI set up given all the extra things I'd have to get just to make it work, or will the simpler set up get similar or even better results?

Thanks!

 

I wouldn't spend the time in a long runner setup unless it was a FIRST. Stock type stuff is more buck, less bang, more finicky.
If you go efi, I'd skip factory ecu as well unless it's a 24x 0411 pcm. You're swapping absolutely everything anyway so you may as well skip the antiquated parts.
Simpler way is a good intake manifold, non ccc qjet or a small holley. A properly calibrated qjet will be close to efi for everything other than cold start related stuff. Depends on how far you want to go for effort and money.

 

I'd go with the carb on that build. Nice and simple, plenty of air flow, no headaches.

 

TPI is a massive upgrade over an aftermarket carb in terms of driveability. I would consider aftermarket EFI too or a factory carb. An eldelbrock or holley will never give you what EFI can. Maybe go with a first unit or a Holley EFI unit

 

Thanks for clueing me in on FIRST. I'll definitely give them a look!

As far as staying carbureted, I'll take a look at some different intake manifolds... Edelbrock Performer comes to mind of course, but I know there are a few different brands out there, especially on Summit Racing which are cheaper and get similar results.

Yeah, I'm thinking the same thing. Not sure what I'd get with the stock cast iron intake vs an aluminum intake vs TPI set up, because I don't have the facilities or money that somebody like Richard Holdener (YouTube guy who does all kinds of side-by-side comparisons on all sorts of engine kit) but I do see a lot of pros and cons of doing it either way.

 

Speaking of Richard Holdener, he did a TPI shootout on his channel, and I'm kind of intrigued by this TPIS "MiniRam" set up. Kind of reminds me of the LT1 intake which I'm familiar with. I'm sure the cam in my 95 9C1 Caprice is similar to what I put in my firebird, and the Caprice is obviously very drivable even with the short intake runners on the LT1 intake. Of course it isn't SFI like the LT1, it just looks similar lol. As for the tests he did... I'm not sure about his methods, or his choice of engine... but it is what it is.


*EDIT*
Worth noting at the end of the video where he finally got to the carburetor test, the carburetor did pretty well. Held power through the whole curve with plenty of low end and top end respectively. With a Q-Jet I'm sure it would do just as well even with a factory intake. It's just a matter of which I value more... simplicity or convenience.

 

Now that was interesting. Spend a whole lot of money and improve the power with the 383 stroker, or slam on a dual plane intake and carb and pretty much equal the best of the EFI units. I would have liked to see a dialed in Q-jet in that last test too.