'88 TBI Build

[Powerhouse Ranch]

Alrighty gentleman (and ladies). Just tore down the 350 from the Jimmy and some decisions were made.

So the previous owner (you should've seen this guy) tore it down and "rebuilt it" and never got it running again because he had pinched the exciter wire that goes to the starter under the valve cover and almost burned the truck down. So i probably have about 30 minutes total of crappy run time on this motor, just getting it to temp, etc. Me and my father found out that the entire bottom end has been redone professionally. Assuming he got the short block sent out and he did the rest. This makes sense because there is a massive quality difference. I'm talking new crank, main bearings are BRAND NEW. Top side, a new head gasket almost failed already and he had the EGR ports on the intake completely clogged up. Now I'm unsure if he was running the truck and had a severe failure like head gasket and warped the head or if he just didn't torque it right. I DON'T KNOW.

So anyway, I've been going back and forth on what i'm going to do with this motor. Originally i was going to trick it out and throw tons of cash into it. Then i really thought about it and compared to my dad's '87 TBI dump truck and it runs fine. So then i was going back to "go through it and make sure it's good" and run stock just to get it on the road. NOW today after teardown my dad says that it would be a waste of a brand new short block to run stock and that it should be a runner.

Now my old man's been around the block more times than i can count and he's the one who started my Squares passion in the first place. So when he says something like this to me, i tend to listen. Keep in mind, i've yet to rebuild/build a motor and will need some help. Especially with what's planned here. SO HERE'S WHERE I STAND RIGHT NOW:

-TBI to EFI Holly Sniper
-Chevrolet Vortec Performance cast-iron heads
-Intake manifold to accommodate heads and Sniper
-Rollers

This is what he ran by me. Told me to find someone who has done the swap from TBI because it's proven. So what i'm saying here, has anyone done a similar swap? If so, what parts did YOU get and how did you go about this? Any information or tips that i need to know for this, fire away. Thanks guys.

First picture is from PO's teardown, sorry it's not the best but it's all i got. The rest are from me today.

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[Powerhouse Ranch]

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[SquareRoot]

Sniper is TBI. TBI is halfway to EFI. Sniper sucks, ask me how I know. @bluex will try to convince you otherwise.

 

[Powerhouse Ranch]

Sniper is TBI. TBI is halfway to EFI. Sniper sucks, ask me how I know. @bluex will try to convince you otherwise.

i got that, jumped into another thread after posting in which members were saying TBI is EFI, agreed, my bad.

I've seen Sniper first hand be good and heard plenty of great things. But i am open to hear the bad as well.

 

[SquareRoot]

Look at Edelbrock Pro Flo. Cost is a wash in the end and you have true sequential EFI. It's also a dry system and throttle response is night and day. Tech support is also 10x better. If TBI was so great GM would still be making it.

 

[AyWoSch Motors]

You thought about TPI swapping it?
Stock GM parts and equipment, keep your same bottom end, but tuned port injection top end. Its an option.
Theres someone on here that have a TPI 350 in their truck.

And I'm not just trying to sell my stuff here, but FYI have a complete TPI setup off my 85 vette if you're interested

 

[Powerhouse Ranch]

OR OR OR would it be feasible to just do bigger heads and intakes, but keep the TBI. I mean I had no problems with it, i had new parts for the setup. I'd hate to change it all and switch sending units and tie the truck up longer. The main question is, do they make a matching intake for the better heads still fittable for TBI?

 

[bluex]

Sniper is TBI. TBI is halfway to EFI. Sniper sucks, ask me how I know. @bluex will try to convince you otherwise.

I dont try to convince anyone. We all know you had a bad experience with it. Mine works great and so do the roughly 12 or more other ones I've installed or fixed the bad install on. I just do the same thing you do, which is tell my experiences with them. Just like anything manufactured in life some mistakes are made. You got a bad one an that sucks, it doesn't mean that every single one of them is bad.

You love to hype the Pro Flo, I don't necessarily care for it but my experience with it is limited so I don't comment. I personally don't care for their software interface an the tuning options are very limited compared to holley but are slightly better than fitech.

OP no matter what system you go with on the fuel system side I would do the 87 tank an sending unit an then if the EP381 pump can't supply your HP Walbro has several options that can. As far as a Sniper, mines been great for 4 yrs now and I've been involved with many more through the shop I ran. It's not a bad system but there are certian things that need to be done for the best performance and you need to be willing to learn the basics of the system an not be scared to use your laptop for it occasionally.

TPI would be great on a truck motor, but I wouldn't run the factory computer setup. Not many people tune the chips anymore an they are not as adaptable to chages as the OBD2 stuff.

I have a TPI that I plan to run off a Holley Terminator on a 383. Should make for a very torque happy setup, which is perfect for a truck...

 

[AyWoSch Motors]

OR OR OR would it be feasible to just do bigger heads and intakes, but keep the TBI. I mean I had no problems with it, i had new parts for the setup. I'd hate to change it all and switch sending units and tie the truck up longer. The main question is, do they make a matching intake for the better heads still fittable for TBI?

I like that idea. Id say vortec heads, and an edlebrock performer for TBI.
Maybe even a slightly heavier cam and headers. Thatd beaf it up well..

There are hop up kits for TBI too. Higher flowing injectors, new regulator, new pump, and thatll kick but

 

[SquareRoot]

One important note. You don't want TBI or carb on a Edelbrock Vortec intake manifold. It doesn't have a heat crossover and its a PITA in the cold because the fuel puddles at the bottom of the manifold. It was terrible with my Sniper at temps below about 50.

 

[Ricko1966]

Now here are some problems,vortec heads won't take much cam without reworking them, square root already mentioned,and I will state it again,vortecs don't like wet manifolds. Lastly Vortec heads require vortec specific intake manifolds,which can be pricey. Example Vortec manifold for TBI expect a price tag about 500.00 for all this money to make so so heads work so so in warm weather,you can spend less to have better heads( think aluminum summits) that work in all weather,will take standard SBC intakes,and won't require modifications to run most cams.

 

[AyWoSch Motors]

Yeah, second thought, maybe not vortec, ive heard those horror stories too, just forgot.

 

[mcarlo86]

Take a look at this website. I had this guy burn a chip for my suburban. Lot of interesting stuff on TBI mods including build ideas.

TBI CHIPS Home

TBI CHIPS Home

harristuning.com

 

[bucket]

One important note. You don't want TBI or carb on a Edelbrock Vortec intake manifold. It doesn't have a heat crossover and its a PITA in the cold because the fuel puddles at the bottom of the manifold. It was terrible with my Sniper at temps below about 50.

Can someone explain to me how Vortec heads are any different in this regard compared to other aftermarket heads with no heat crossover or running intake gaskets with the crossover ports blocked?

When I was younger, I daily drove my hopped up 327 with the crossover ports blocked. I had no troubles in winter.

 

[SquareRoot]

Manifolds that fit the bolt pattern of Vortec heads don't have a heat crossover. The manifolds are designed for a "dry" system meaning they use port fuel injection. The manifolds only flow "dry" air, not air mixed with fuel like you have with TBI or carb. When wet air encounters a sharp angle, i.e. an abrupt change in direction, the fuel separates from the air due to different densities. Cold manifolds condense air/fuel mixtures. When the charge hits the bottom of the manifold it has to make a 90 degree turn. This is where the separation occurs. This is also why you will see a waffle pattern cast into the manifold at this location. A manifold with a heat crossover helps keep the fuel/air charge in a vapor (lighter) state and less prone to separation. Think filters that spin the air to separate dirt particles, same for canister vacuums. Same principle. Vortecs are ok once warm but a PITA when cold. This gets annoying on a daily driver. Hope this helps.