mild 350 TBI build

[Low87]

I've been reading this forum & others trying to get to where I can ask reasonable questions.

I need to replace the motor in my '89 Jimmy. It needs to be reliable moreso than powerful. If I can get mileage in the 15 range I'd be very happy.

As much as I'd like to swap in a vortec, or better yet an LS, that's not going to happen. I need to keep this simple and downtime a minimum. No added problems.

Tempted to drop in a Goodwrench crate, but I read where TBI heads just plain suck. So what I want to do is build a reliable TBI with operational improvements where available.

I want it to work together, and I will change exhaust & gears to improve driveability.

looking at the ported TBI from Marine Performance Parts
http://marine-performance-parts.com/cfmtechportedthrottlebodyforgmtbi435057.aspx
aftermarket heads (no idea)
I'd like roller cam & rockers
short block from ?
stock or Edelbrock manifold, matched to heads
larger battery cables, 8.8mm wires, delco plugs

I have a MSD coil & Pertronix distributor to use.
Fuel pump, sender, filter have all been replaced recently. Can swap filter out if necessary.

No idea what gears would be good. Stock height, may lift up to 4" over the next few years. GM 10 bolts, will likely stay that way. 33x12.5x15 tires.

I'd appreciate some guidance. My lack of engine experience (I've done the swap on my '87, but that was a straight Goodwrench long block swap) is making this a lot to digest.

Budget is still in the works. I've got some other necessary projects to complete with the money coming in, most importantly with the engine is saying bye bye to rust.

 

[dyeager535]

Obviously there is a bunch to it. But if starting from square one, and roller cam/lifters are in the running, I would highly suggest a later block (one piece rear main) that is already roller. The aftermarket roller stuff is very pricey, and unless it's been improved since I bought mine, not as good as factory.

I don't *think* there is any reason that someone would say a later roller block is not a good idea. The one piece rear main is always better, and the roller setup is proven. The good thing about a block is, unlike other parts, you can buy it way in advance and not have to worry about changing your mind, if an LS or diesel swap isn't in the back of your head.

 

[Low87]

Thanks, didn't know later GM blocks were roller. Any ideas what years I should be looking at?

 

[dyeager535]

May need to do some digging, but I think all '86-later blocks were one piece rear main, and all *car* blocks 1987+ were roller, trucks got roller in 1996. I would think the later vortec blocks to be the better bet, simply based on age, but other than that, no real difference I am aware of.

 

[Low87]

Looking into it. Sounds like a factory roller = Vortec. From what I read on using a Vortec with TBI is you need a $400 GMPP manifold, do some modification to make the EGR work, and use a larger fuel pump. Some people retuned, some said their chip worked just fine as-is.

 

[dyeager535]

First things first. A Vortec SBC block is essentially the same as any other small block. There is no requirement for you to run Vortec heads even if you run a 1997 truck block. Vortec blocks are all roller, but as I said, so were all car blocks after 1986 or 1987. The truck blocks were also set up for roller (holes for lifter hold downs, etc), but you might as well get all the pieces.

However, if staying TBI, you want Vortec heads, and you don't need EGR for emissions, the easiest way is to buy a Vortec to carb intake, carb to TBI adapter, and be done with it. EGR is the ONLY reason the GMPP intake is so pricey.

If you need EGR, it would probably be about the same price to get some nice aftermarket (non-vortec) heads, so that you could continue to use the "older" style intake bolt pattern.

Anyone who says their TBI ran fine as-is after component swaps really doesn't have a leg to stand on. Unless they have datalogged their setup, they cannot make that statement. Just because a motor FEELS like it runs good, does not mean it is actually running as good as it can.

 

[Low87]

We don't have emissions testing here (no inspection at all), so I don't believe I need the EGR. What would be affected if it wasn't present?

 

[dyeager535]

Ongoing debate about EGR and what the benefits/cons are. I won't get into it. Suffice it to say, if it's "turned off" in the PROM, you won't notice any difference. When it comes to a cheaper/easier way to do something, EGR is absolutely something that should be considered "optional".

 

[Low87]

Thanks again, next question;

I'm not having any luck finding a local shop that can run a custom tune on the chip. Since I plan on limiting my down time to a long weekend, can I send a chip out to be burnt using the specs of what I plan to put together? How's the best way to handle that?

 

[dyeager535]

Unfortunately I can't recommend TBIchips.com anymore. I've heard enough to think that sending people there may be a bad idea anymore. Maybe he's got far more satisfied customers than non, but I can't know that, I only hear the bad.

You can certainly set yourself up for success by purchasing an ALDL cable http://www.gearhead-efi.com/Fuel-In...e-Forum-Buy-ALDL-Cables!&highlight=aldl+cable, and downloading tunerpro RT.

I hate to say it, but to do it right, you are going to have to get into the tuning community.

With a laptop, ALDL cable and Tunerpro, you don't need a handheld scanner, so no matter what, you end up with good diagnostic equipment that will be useful.

 

[eagle mark]

Thanks again, next question;

I'm not having any luck finding a local shop that can run a custom tune on the chip. Since I plan on limiting my down time to a long weekend, can I send a chip out to be burnt using the specs of what I plan to put together? How's the best way to handle that?

I always recomend a hands on tune, but there's very few who even touch anything ODBI anymore.

I do a lot of vehicles, but this one is my specialty!

If you can't find some one give me a PM when you get your motor build in order, I've done chips for just about any build. You can have chip in hand to run. Probably won't need a retune but I love to see data and fine tune. Need a laptop and cable, I supply my own files for data logging with TunerPro RT.

My recomendations for a TBI motor:
1. Vortec heads.
2. Cam specs that list RPM as 0 to whatever. This will usually be under 224 duration @.050 and 113 or better lobe seperation.
3. Adjustable regulator and fuel pressure is dependent on HP of engine. So more engine means you may need to replace pump. HP also determines Injector size, there's only so much pressure for stock 5.7L injectors before it becomes ridiculas, then a much lower pressure and 7.4L injectors are in order.
4. 5000 = RPM engine will need bored throttle body or one from a BB, thenof course your'll need the exhaust end with headers exhaust.
5. Headers, don't buy cheap, get quality coated long tubes, my Headman Elite looked like new after years and never had a leak. Coated also keeps heat in and goes out exhaust and does lower underhood temps.
6. Cold air intake, no open element filters...

Some people retuned, some said their chip worked just fine as-is.

A stock chip will run a mild build. Anyone who said a stock chip ran a mild or moderate build ran good? Just has no idea what good is!