I have a dilema and a decision I need help with...

[Crispyr1]

So I have a 68 SWB C-10 without posi. I have PB, PS, Disc brakes all around. So stopping isn't an issue. I have a 400sbc that is tuned port injected but my 700R4 just went out. I originally wanted fuel injection because I wanted it to be as close to a daily driver as possible. I got the raw end of the deal with a mechanic and the tuned ported 400 is what I got. Don't get me wrong I love the 400 but it doesn't give me the functionality I need. So I was thinking of going with the LS1... any thoughts? Has anyone done this, that could tell me the pro's and con's of the swap, Headaches, and what to expect? I hate having to wait for my truck to warm up and the fuel economy is super bad, will the LS1 be any better? Your thoughts and opinions are appreciated. TIA!!!

[Redline novdog]

Don't quite feel your pain. A tune port 400C.I. small block and a 7004r doesn't give you functionality??? Rebuild the 700R4 to meet the torque of the 400. Which should be/could be outrageous !!

[D-rock1981]

what functionality do you need that the 400 won't give you? The 400 was a functional moter in millions of cars and trucks.

[jakewalter]

Is there a better place to spend your money (body, interior, wheels and tires, suspension)?
2X on the trans rebuild.
It sounds like you might need to take it to a professional and have them set the 400 up.
The 400 is more power than you'll ever need on the street.

Just my opinion,
Jake

[GASoline71]

Originally Posted by D-rock1981

what functionality do you need that the 400 won't give you? The 400 was a functional moter in millions of cars and trucks.

I don't know about "millions" as the 400 was a limited run engine used mainly in trucks.

The TPI is a "decent" fuel injection system, but it has it's perks and twerks. It could be really limiting the 400 if not set up correctly. Remember it was a "performace" injection system that was thunk up in the smogger hey-days...

Your transmission could have also given you fits as well. If the TV cable was not set correctly it could have led to the transmission failure. It needs to be set dead on correct or catastrophic failure is the result.

I'm betting that if the FI is set up correctly and you have a good 700R4 behind it, set up with the proper torque converter, and the TV cable set correctly you will be back in business.

Or... you could drink the LS Kool-aid and go that route. Nothing wrong with going that route as numerous cats have done it with great success. S if you're looking for your reason to talk yourself into going the LS route... here it is.

Gary

[motorcritter]

TPI is a very efficient fuel injection system, not as advanced as the LS set-up, but miles ahead of carburettors (no pun intended). That said, an LS is going to give you more power, but more expense to do it right. The 700 R4 is a good unit, can be built to newer (stronger) specs and as noted, the TV cable is the weak link. Any LS you install will probably have a 4L60E or 4L65E behind it- which is an updated 700R4 with electronic controls- less headaches. As usual, you pays yer money and ya takes ya pick. I vote for rebuilding the 700R4, and dialing in the TPI even better.
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[hugger6933]

There is a LS-x section on here go to the home page and roll down till you find it. The TPI when setup correctly should make you happy. The truck probably needs a tuned chip burned for it if you can find someone that still does that kind of thing. I built an S-10 with a TBI in it and before the tune I got 18.6 miles per after I got 26.2. Same road just a return trip from the tuners. It took a couple of times to get it but when he did the motor the truck and I were all happy. You should have the equipment to make that truck a torque monster the 400 was made for torque and when you add the TPI it should just expound on that. I think before yanking out what you have maybe consider a tune on the computer to make it more for the 400. You may have a 305 tune in it if you haven't had it tuned and that would disappoint anyone. Jim

[Zane M]

Arguably the LS is a better set up in the modern world-provided it is installed and tuned correctly.

With that said, A TPI 400 should provide you with a nice, reliable powerplant that should serve daily duty easily.

A properly running/tuned TPI set up should not require any warm up time, and should net you decent gas milage. The LS maaayyyy get you a little better mileage, but not so much better to necessarily justify the additional cost.

If you give us some more details of your issues, we may be able to point you in the right direction in getting the existing set up running appropriately.

[BenC/10]

Another possible solution could be, upgrading to a more "modern" f.i set up? Such as msd atomic efi, fast efi? They tune themselves

[Crispyr1]

Thanks a lot guys for the help. I tried to post pics of my setup so you could give more info on it but could not upload. On the 400 block where can I find the numbers?

[PAWS 72]

Same place as the 305 and 350's.

Theres a pad on the passenger side head in the very front.

[franken]

What does functionality mean and in English, what do you need?
Next, in English, how much money do you have?
Finally, what doesn't the vehicle do that you want it to?
No idea where posi fits here...