# '68 Chevy P/U Conversion to FI/700R4?



## o_jay66 (Oct 17, 2008)

Hello - I'm new to this part of the forum (usually prowl the carpentry, etc), so please pardon my mistakes, etc.

I'm looking for an early model Chevrolet/GMC pickup for my yougest son. I've restored several 69-72 trucks for my own use, and just finished a '65 2-door hardtop Impala for my middle one, now it's the 'baby's' turn!

I found a '68 that the current owner has sorta combined with a '92 that lost the truck/deer battle in this part of the country! Anyway, he's taken the fuel-injected 5.0 and 700R4 out of the '92 and has it setting in the '68. The entire wire harness and all the engine-mounted sensors are still in place, and I can have any of the parts off the '92 to make it work...if I want to go that route. 

I also have a '77 chevy truck with running 350/350 that I could always use to finish the '68.

My question is how much of a pain will it be to go ahead and use the '92 stuff? I'm a good wrench and know my way around these trucks, but I'm not sure what it takes to run the TBI, etc on the motor, and how to deal with the lock-up on the trans. Any input out there?

Thanks,


----------



## 47_47 (Sep 11, 2007)

It's doable, but I think it would be more work than its worth putting the 92 in. You will have to also install the computer, change the fuel lines and other emissions systems (EVAP...). I'd install the 350 and sell the '92 engine.

I'm more interested in your '65 Impala. 327 or 283?


----------



## o_jay66 (Oct 17, 2008)

283/Powerglide. Bought it for my oldest son from the original owners' granddaughter with 76,000 miles on it. Now it's got about 90,000 on it and runs like a sewing machine, doors shut smoother than my new truck, it's a real peach! I re-painted it two years ago, last summer I switched out the PG for a TH350, I just got done re-upholstering the whole interior, and I'm going to paint it again in the next month or two for the middle son. Check out my photos under the kid's folder - there's a pic in there where you can see the front part of the car.

Now i'm down to the last kid....and he wants a truck! Another prob i thought of is fuel pressure to the TBI. An early model pump won't work by itself will it?


----------



## 47_47 (Sep 11, 2007)

Sweet ride.:thumbsup:

No, the '92 TBI will probably need about 40-45 psi to it (have to look up the spec) and should have had the fuel pump in the tank.


----------



## Jeeper1970 (Nov 11, 2008)

You'll have to replace the fuel tank with the fuel injected fuel tank and in-tank pump. You'll have to replace any rubber fuel lines to handle the additional psi for fuel injection. You'll also want the O2 sensor from the exhaust.

It is a lot of work, but I think it's worth it. Once you get the bugs worked out, fuel injection is more reliable and provides better fuel economy. The 700R4 also has an overdrive, does it not? Again, will provide better fuel economy than a 3-speed Turbo 350.

If your son wants more power, it's as simple as spending a couple/few hundred on a chip/reprogrammer and plugging it into the computer.


----------



## jimmyfloyd (Sep 29, 2008)

not sure if this will help. google found it: http://www.americanclassic.com/Google_Base_HTML_Pages/LIT-66-1968.htm


----------



## o_jay66 (Oct 17, 2008)

Thanks for the gut-check guys. I think the motor swap sounds like more of a hassle than I want, especially for a 16 yr-old kid who only has to drive to school and back. 

I may still try the overdrive, that would potentially save the old man here some bucks on gas, and it may not require all the hassle that the engine would. I can make the thing fit physically, what I'm wondering about is dealing with the lock-up converter. What locks/unlocks the thing in a normal installation?


----------



## Mort (Nov 26, 2008)

700R4 isn't computer controlled that year. Should be vacuum controlled.


----------



## wire_twister (Feb 19, 2008)

Never seen a 700R4 with a vacuum line run to it. The shifting is controlled by a throttle valve, which is actuated by a cable hooked on the throttle body by the throttle cable. The converter lockup is controlled by the computer thru the 4 wire connector on the drivers side of the trans. This is a swap that is well worth the time if you plan to keep the truck and drive it, I have an 80 ElCamino that I am putting a 6.0 Vortec and 4L60E in.


----------



## Mort (Nov 26, 2008)

wire_twister said:


> Never seen a 700R4 with a vacuum line run to it. The shifting is controlled by a throttle valve, which is actuated by a cable hooked on the throttle body by the throttle cable. The converter lockup is controlled by the computer thru the 4 wire connector on the drivers side of the trans. This is a swap that is well worth the time if you plan to keep the truck and drive it, I have an 80 ElCamino that I am putting a 6.0 Vortec and 4L60E in.


That's what I meant. :biggrin:


----------



## oregondiy (Oct 24, 2008)

If the engine, trans, and wiring harness are already in it I say go for it. These engines are not power houses but are very simple and reliable.
The fuel pump only puts out about 12 psi on that engine. You can either use a in tank pump or they make external pumps just for this purpose, I have one on my toyota 4x4 with a tbi 350 in it. The computer will just plug into the harness and the connectors will pretty much just plug into the correct sensor. Go for it.


----------

