TBI spacer, anyone done it?

Hi all. Anyone done this? I've browsed through the archives and the supplier parts lists, lots of different spacers out there, lots of opinions. I'd love to hear from someone with a wagon who's done it. How was the install? Any hood clearance problems? Fuel line length issues?

Oh, and any difference in the performance?

I've got to rip all of that TBI stuff off to replace the intake gasket soon so the spacer mod is on my mind.

I did one way back in the day on my TBI K5 Blazer. IIRC, it help with low end torque and better mileage by a bit. Seemed to smooth out the throttle response a bit, too.

Is there room for the factory air cleaner assembly with a spacer on these cars? You may need to switch to a fwd 4.5l caddy intake elbow and build your own PVC/cone intake setup if you do it.

toomanytoyz wrote:

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Is there room for the factory air cleaner assembly with a spacer on these cars? You may need to switch to a fwd 4.5l caddy intake elbow and build your own PVC/cone intake setup if you do it.

Good point, I wonder if an exhaust upgrade is a better first step? I'm finding some nice info over on the thirdgen group too.

Here are some places to check:

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You can get a fuel line with a Schrader valve from a 91-92 Fleetwood with an LO3/5 so that you can check your fuel pressure. It is a direct fit. The gauge adapter for the marine engines are difficult to install, and you have to rebend the fuel line to make it fit. I have installed one of the gauge adapters, and the Caddy line is a lot easier. The 93 Fleetwood has a fuel line that will fit also. It is a little different shape, and the Schrader fitting is positioned at a different place than the 91-2, but fits in the same place (it does not have the S bend on the passenger's side).

I believe the 1 inch spacer will fit under the TBI and you will be able to close the hood. You can also put another gasket under the injector holder (with custom length screws), and open the intake for more airflow. The spacer will make the intake runners longer, and put the torque curve slightly lower. It will not change the maximum torque or HP. If you put headers and duals on the car you will get about 25 HP. If you can find a cam (roller cam), injectors, and computer from a 9C1 with a 350, you can get about another 25 HP. You could use the LT1 cam in place of the 9C1 cam, and the computer should be able to handle it, because the lift is close to the 9C1 cam. There is some commentary on the forum about it, because I put the LT1 cam in my LO5.

Thanks guys, I'll keep digging and thinking about it. It's amazing how this mod is either "a total waste of money" or "you can really feel it making a difference," depending on who you talk to.

you'd need to readjust the tv cable, but if the computor isnt rechipped does any mods pay off?

The computer can compensate for some mild mods, but if you are going to change anything of any consequence (cam, heads, larger TBI/injectors) you will probably need some electronic tweaking. The main issue is fuel/air mix/volume. You also have to make some mods as packages. e.g. cam and injectors. A lot of the mods will still work with the original chip. You can probably put headers and duals on it, the TBI spacer, gasket under the injector/regulator mount, and even clean up the intake of the TBI without a custom chip.

I put a 1" tbi spacer on my 1995 Chevy G30 van, it seemed to help low end torque as Bill said. I then put a Jet chip in it, and a Hypertech power bowl (goes between the top of the tbi and air cleaner, shaped like a soup bowl). Gas mileage stayed the same, but it hit 60 from a dead stop sooner, by about 50-60'. I used property lines on a rural road by the housing track I live in to figure the 50-60' distance.

If you do this, now is a good time to put an inline fuel test port in the pressure (feed) line, that way you can check your fuel pressure much easier.

200OZ wrote:

I put a 1" tbi spacer on my 1995 Chevy G30 van, it seemed to help low end torque as Bill said. I then put a Jet chip in it, and a Hypertech power bowl (goes between the top of the tbi and air cleaner, shaped like a soup bowl). Gas mileage stayed the same, but it hit 60 from a dead stop sooner, by about 50-60'. I used property lines on a rural road by the housing track I live in to figure the 50-60' distance.

If you do this, now is a good time to put an inline fuel test port in the pressure (feed) line, that way you can check your fuel pressure much easier.

The fuel line from a 91 or 92 Cadillac Fleetwood with an LO3/5 has the port already installed on the line. It bolts up to the B-body perfectly. You can also use the fuel line from a 93 Fleetwood, although it is a little different shape, it will still bolt up perfectly.