I need sujestions and to check my facts.

Well, this project is in the very beginning of the planning stages. I am finally to that part of my life where I can build an engine right, spending my money smart, but not having to pinch pennies the whole way.

I have a 1984 K4 as my victim. I will be honest with myself and all you, I am lacking hands on experience, especially with TPI set ups. I think TPI is cool looking, and I think I have a lot more potential horsepower and fuel ecconomy with a TPI setup than with a carb.

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The GOALS

Enough power to get a full sized K5 anywhere I want to go, and then hopefully back out. An offroad BEAST.

Good enough fuel ecconomy I can drive it where ever I want to go

Under $5,000

The questions

Will a factory rollor cam increase ecconomy by enough to make a REAL diffrence?

How much of a diffrence does Speed Density verses MAF make? Is Speed Density really better?

Are their any sensors on the side of the block that wont like large amounts of water?

Will honing the cyclinders cause the EFI to need to be RE-tuned?

Is there any way to run TPI without a return fuel line?

Would you choose a 350 with a four bolt main, OR a 350 with a factory rollor cam?

Would stroking the engine take away fuel ecconomy by TOO much? How hard would it be for a TPI newb to program it to accept this?

The TRUCK

1984 K5 Blazer

Carborated 305

Automatic transmision, may have been swapped out for a non overdirve.

3.08 gear ratio (ewww)

The plan, in sequence.

Get a 350 or a parts IROC with the 350 and all the fuel injection already attached

Place the 350 in the truck, and hook up the existing carb to the new engine, make sure all is well.

Mount a tank with an in tank pump in place of the existing tank, hook up the Fuel injection, and note the diffrence in Fuel Econnomy

Learn to burn new proms for my TPI Blazer

Replace Heads and cam with more better aftermarket parts (Sugestions are wonderful)

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Im sure some of you are of the opinion I should build the engine exactly how I want it before I put it in, then make the TPI bend to my wishes, but I would rather spend alot more time doing this and someday get it how I want than to do it all at once and never get it tuned right...

Just want some thoughts and opinions and sugestion.....

 

First, your concept is not that far out. It's been done before (by me) on various vehicles:





TPI should be a good fit for that application. A MAF TPI would be easier to tune, more forgiving, and should flow plenty for a low-end torque application such a a Blazer.

Fuel mileage and driveability should easily improve, but it would be even better with an OD/TCC lockup setup, which may be a challenge. IIRC, the Blazers of that vintage were using a Borg Warner XFER case, and may not fit up well with a later OD auto trans.

 

That year came with either a Turbo 350 or a Turbo 700, so if it's factory three speed auto, you have a Turbo 350. Now, that's not a bad thing. The Turbo 350 and the Turbo 700 have the same bolt pattern for transfer cases. Just the output shaft is different. There is a conversion piece to change the output shaft so it's the same as the T350.

If you do that, you can get a Doubler from ORD at some point, swap out the NP208 it came with, and then swap in a NP203 range box with a NP205 on the back of it. Get it with a 2" up rotation, and have someone fab you a nice crossmember.

Get a built up 4x4 700-R4, and see if they can install the output shaft for ya. Things would be easy from there on.

If the IROC runs, a straight swap would be easy. I think the sensors would be fine with water as long as you kept using sealed connections and watertight wire repairs.

 

Im pretty sure the only Turbo 700 trans is the Turbo Hydramatic 700r4....no 3 speed 700s...

 

The transmission is mystery. I believe it came factory with an OD trans, but it is either been swapped, or something is screwed up, because I can only shift into 3 forward gears.

I find it strange that you are all suggestion an OD transmission, my grandfather, who has worked at a transmission shop for like, 30 years, says that all Chevy trans with OD are weak and a waist of money...

 

Here's you a few good resources:
www.advanceadapters.com
www.stealthconversions.com
www.jaguarsthatrun.com
www.700R-4.com
www.s10forum.com
www.v8s10.com or is that www.s10V8.com?
This is all I remember from doing my own such swap to an '89 S-10

 

Not to argue with anyone, but I've found just the opposite to be true. Certainly, all transmissions have their weak points, but in general, the HydraMatic OD transmissions have been proven fairly stout. As a matter of fact, there are numerous high-HP cars using them without problems. The TH200-4R, the TH700-R4 (and its derivative, the 4L60), the 4L60E, and 4L80E are pretty reliable in stock form, and can be built to take a lot more power than the factory ever intended. Those have been around for more than 30 uyears. Perhaps the fact that they have been around so long, and have been installed in so many vehicles is why some people have that opinion.

By comparison, Ford couldn't keep a transmission design for more than 15 years without changing it completely, Chrysler never had a good OD transmission, and the imports don't offer anything outside of a ZF/Getrag that can take any kind of torque for a couple hundred thousand miles.

Turbo Buicks launching on two wheels thrive on TH200-4Rs. Millions of F-Bodies and Y-Bodies have been abusing TH700-R4s and 4L60Es for decades without a high incidence of failure. Some pretty heavy duty trucks have used those same designs since the 80's without trouble.

 

nothing against ur grand pappy but alot of times u will see alot of older guys call newer technology inferior because they have a proven formula for power and sucess and they dont want to stray from that path. ive seen countless local guys utterly dumbfounded when a built LSX 4th gen f body runs all over a big block 1st gen at the track they love to stick with the addage of "they dont build them like they use to" wich is often true in car styling but hardly ever in power and durability....,
stock a 7004r has a weak spot or two but not much weaker then a th350 and the aftermarket has stepped in and made some stout parts.... check out those links atilla provided and ull find some good trans.......

 

Well, my big hurdle right now is still with the engine. I kinda want to put it together the way I will eventually want it while it ISNT in the truck, but at the same time I worry about trying to set up the fuel injection to like an aftermarket set of heads and a different cam...

Gr, I wish I had something to learn how to tune EFI on, but somehow I think the 4.0 on my Jeep is an entirely different beast.
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This makes alot of sence... We have gone round and round about the T-5, I tell him the tranny is weak and cant put up with any real power, he tells me I am wrong and then says he has seen less T5s in the shop than the T56s....

 

A MAF system will require a lot less finite tuning. Using the MAF tables from an ARAP binary file and adjusting the major parameters to suit your build should be all that is necessary to get you running successfully. That would be the case regardless of which heads, cam, and exhaust you might install. As always, there is always room for finer tuning, but that is likely the easiest path to success.

I've run TPI on 1970's smog-dog engines with almost microscopic valves, no compression, almost no bumps on the camshaft, and poor-flowing heads. I've also run them on 10.4:1, big valve aftermarket heads with tall, long duration cams, and they seem to be very forgiving with even nearly stock programming.

You can mount a fuel pump either in the tank or outside it, but the in-tank pumps are quieter and seem to last longer. In either case, you'll need to run a return line, but your truck should already have at least two lines to the fuel tank, and the EVAP line is suitable for use as a fuel return. A little steel tubing work in the engine bay might be all you need:



The wiring may take the most time of all your tasks, but the relay panel, ECM, and most of the connectors can be installed inside the vehicle. The sensors which are left on the engine can be fairly water resistant if the connections are prepared well, just as Scary 1 advised. The only sensor which might be somewhat sensitive is the MAF, which will need to be mounted securely and ducted so that no water can enter the sampling tube.

 

I have a 1986 K5 Blazer 6.2l diesel with the 4spd overdrive. Its at 150 thousand miles on the original transmission. I only use it for plowing snow the last ten years and occasional use when I need to haul something heavy on a trailer. I think there were some upgrades in either 85 or 86 for the transmission. Also I think the diesel tranny was supposed to be slightly different from the gas engine trannies but I think the biggest help was how low power the 6.2's were.I had one coworker with an 84 Astro van who for a while when he first bought it seemed to blow his tranny every six months or so. Most of the serious offroaders around hear seem to prefer manuals. If you go with a stroker make sure your tranny is rebuilt by someone who has experience building 700's to handle the kind of power you could be putting out. Unless you are going mudding a stock tpi and double transfer cases will give you all the grunt you need.

 

Incidentally, and as some have pointed out, although this is not a ThirdGen specific thread, the content applies to converting a non-TPI system to TPI, along with the associated obstacles.

Even though it is relevant, since it isn't directly ThirdGen content, this thread should be closed and the original poster will have to continue to gather information regarding a carb to TPI swap by disguising his vehicle as a 4WD K5 "Camaro."

When it gets closer, there will be lots of helpful information available at the DIY PROM forum and here at TPI, among other forums on the site.