Who has TBI?

[1972]

I have a 1989 C1500 with a 350 TBI motor and a 700R4 transmission. I want to put this combo in my 1972 C10. Is there anything tricky/difficult about it? The donor truck is complete and runs. There are a few things that I am thinking about:

I still have the gas tank behind my seat (in the 72) and I kinda' like it there, so what will I need to do for a fuel pump?

The 72 has factory air, can A/C lines/hoses be made or bought to connect to the factory A/C system? Both compressors are R-12, is there a 134-A conversion kit? Or could I use the kit and a 134-A compressor from a newer truck?

I think that the 72 still has the externally regulated alternator, is it difficult to re-wire the truck for the 89 alternator?

Is it difficult to make the 700R4 shift linkage connect?

I am not worried about exhaust or drivshaft modifications. If there is anything else that I should consider though, post up! Thanks.

[Tx Firefighter]

You'll need an inline electric fuel pump that supplies 9 to 14 psi. You'll also need to return the excess fuel to the tank. If your 72 already has a return line, use it. The TBI unit has two fuel lines that screw into the back of it. Get them when you part the truck. They have a special o-ring fitting on the end of them. One is fuel supply and the other is the return to the tank.

The shift linkage is a direct swap onto the 700R4. No mods required.

Any local hydraulic hose shop can make you the lines you need to connect your factory air to the newer compressor. Get the new lines, so you have the end fittings to install on the new hose.

I believe there is an article in the FAQ about the alternator conversion.

Personally, I'd use a Painless Wiring harness. Well worth the money for the finished clean appearance and easier install.

You'll need to install an oxygen sensor bung into your exhaust system and re-use your rams horn type of manifolds. The later model manifolds will hit the engine mounts if they are the low mount type that most 89 trucks used.

The worst issue will be the 700r4 trans you have out of the 89 model should have an electronic speedometer sensor and your truck needs an older, cable type. There are a few aftermarket solutions out there, but they cost some money.

[1972]

Tx Firefighter - Thanks for the good information. I was planning on still using the old manifolds or possibly even switching to headers. I never thought about the speedo cable though, I'll check at a local tranny shop and see what they say. My friend is getting the body off the truck and I am keeping everything else, so I can always get some parts that I may need.

Thanks again, 1972

[bagged91]

Every he said is correct. I just want to elaborate a little bit more. There are 3 different types of VSS's on the 700R4/4L60.

Your 89 Truck Transmission should have the full electronic type which is basically a sensor with a reluctor mounted on the tailshaft. Unless you are going to use an electronic or digital speedo, put this tranny up for sale and look for one of these listed below...If you do use this tranny, you will need the Dakota Digital SGI-5b universal signal converter to convert the VSS pulse rate to the compatible pulse rate for your aftermarket speedo.

There is also a "hybrid" type VSS found in Chevy Astro's & pre 92? B bodies(caprice, roadmaster, ect...). These have an electronic output but are a gear driven unit driven off of the tailshaft.

There is also another type that uses a gear driven VSS with a cable coming out of it that goes to the VSS buffer behind the instrument cluster on some mid-late 80's cars/trucks. THIS IS THE ONE I WOULD LOOK FOR but the HYBRID one will work also but you will still need the VSS from one of these trans... From what I understand, they can be found if the F bodies. I also believe the 87' C10's will have this type setup...

Remember, you will want to stay with an 87 & up trans. The earlier ones are not as strong...

Hope this helps...
Joe

[1972]

bagged91 - Thanks for the additional information. The truck is about 20 miles from me now, I will check this weekend to see what type of speedo connector it has. If it turns into much of a problem I may just use th TH350 that's in the 72.