Tbi to vortec heads

[TylerZ281500]

only way to tell fully like said is if you pull the intake, if your truck still runs id find yourself a spare motor and start building that one

 

[HCPcustompaint]

I'm in a similar situation to the OP, so I'll just stick my questions on here...

Like the OP, I'm not looking at an engine swap. Yes, it'd be sweet, but it'd also be overkill, especially on my wallet.
What I have is a '90 K1500 with just over 100k on the clock, and has had the engine and trans (manual 5 sp) rebuilt in the past year or so (by previous owner, but I have all the reciepts and records).

Basically, I know the bottom end is good and solid, so why not use it? What I'm currently thinking is that I want to put some Vortech heads on it, a GMPP TBI to Vortech intake manifold, the needed fuel system upgrades, and, of course, the really fun computer tuning part. I'm thinking about using a 454 TBI unit and having the intake drilled out to fit, as well.

The previous owner put a header-back exhaust on it, and it looks like I'd just need some shorty headers to make it a full system. I'd actually like to put a catalytic converter back on it if I can find one that won't chop the balls off the engine.

The engine has a Comp Cam installed already, as well, which, if I can, I'd rather just keep using that one, but it's a pretty mild grind, so I might have to look at some other options.

I've slowly been reading up on the PROM tuning, but it's not exactly page-turning excitement, so it's taking a bit.

Anything I'm completely missing? Is this a decent route to go, or is it a pile of headaches for not much gain? Anyone want to venture a guess on what that combination could make assuming it's tuned right?

 

[TylerZ281500]

seems like youve done some research, first off the gmpp manifold is expensive for the money hit up jegs and get a carb-vortec intake and use an adapter for carb to tbi price is like 130 bucks for a brand new one 454 tbi is nnecesary use your 350 tb and ulitimate tbi mod it and youll be absolutely fine

shorty headers the ebay stainless ones have good reviews, cat isnt necesary on tbi but its an opinion really, mine runs great without it.

do you know your cam specs? definie mild grind? the one im running is about 230 duration 421/444 lift and 112 lsa, tbi likes something around that yanno, i also ran the 460/480 lift cam before on a tbi as well it mostly depends on lsa and duration. other great options are mtc1 cam which is about the same size a hair smaller and lt1 cam is a great choice if you go full roller. but id use yours if it mics out and so on.

as for prom tuning if you havent already look at gearheadefi, they helped me a ton, i had eaglemark tune me a base tune and i took baby steps to get it from there.

fuel pressure, i upgraded to a tpi pump with inline regulotor as did jdyates.

since your manual no trans mods really need to be done, add a decent distributor and new timing set and little stuff like that and your set. i also deleted my egr on both my tbi trucks (tuned it out properly) and never regretted it. ive gone through three engine in my yukon because i thought i could go crazy and found that to not be streetable, then went a bit more mild and needed some money so went back to a slightly less upgraded setup but ive done many vortec swaps. check your compression and all that, its nice to assume things are perfect in your lower end but test them to be positive yanno.

 

[HCPcustompaint]

Thanks for the tips. I've been doing as much reading up as I've had time for. This is my first SBC, though, so I'm pretty sure I'm required by law or something to have some fun with it. lol.

The cam is this one http://www.summitracing.com/parts/cca-cl12-249-4 . I have to admit to not knowing a whole lot about cams. I get HOW they work and all that, and have swapped a few on MC engines, but when it comes to talking duration and all of the technical stuff, I'm lost. I'd rather stick with a tappet style cam if I can, unless it's ends up that it's going to be something that is holding up a bunch of horsepower. It's definitely something I'm going to need to look into more before I decide one way or another.

Good to know on the 454 tbi. For some reason, that seems like a project that sounds like it should be simple and easy, but could turn into a headache quick. Doing a bit of grinding on the tb and adding a few spacers seems like significantly less potential trouble.

For the cats, my truck has a cat-less, manifold-back system on it now. It runs good, and it sounds good, but I'm not a huge fan of the "unburned hydrocarbon" smell. Or, really, pumping any more of that stuff into the atmosphere than is necessary. The exhaust on it is a 2-1-2 system, so I'm thinking that if I put a high-flow cat on each head pipe, it shouldn't be restrictive enough to make much, if any, difference. At least that's what I'm thinking, but, like I said, most of my wrenching has been done on motorcycles, and pollution control parts are usually tossed straight away.

I should mention, too, that my truck is mostly a shop truck that gets used for daily driving, so keeping things a bit conservative and on the "streetable" side is the plan. Not that too much horsepower would be a problem, though. lol.

 

[TylerZ281500]

you might be able to get by id ask the gearhead efi guys, thats a fantastic site. both tb and injector spacers are good, i believe magnaflow makes a decent hi flow cat,

 

[HCPcustompaint]

Thanks much

 

[Rusty334]

Flat tappet cams are fine as long as you use good oil for break in, adjust the lifters correctly.. However, I was under the impression all 87 up small blocks ARE drilled and tapped for a spider?

As for the intake, they make a TBI Vortec intake, to mount a TBI unit on top of Vortec heads

What u referring too when u say spider

 

[Erik the Awful]

First, this thread is seven years old. The people who posted these comments aren't likely to be around any more.

The 'spider' on a Vortec motor refers to the fuel injection system. The original setup used a central injector and individual "poppets" in the intake runners. It's garbage. There is a replacement spider that replaces the poppets with true individual injectors.

If you'd like a more recent thread with information on swapping from TBI to Vortec heads, I wrote up all the info I could and got it stickied. https://www.gmt400.com/threads/how-to-put-a-vortec-motor-in-a-tbi-truck.49463/

 

[Hipster]

lol

 

[Schurkey]

I was under the impression all 87 up small blocks ARE drilled and tapped for a spider?

What u referring too when u say spider

The 'spider' on a Vortec motor refers to the fuel injection system. The original setup used a central injector and individual "poppets" in the intake runners.

In the context of "drilled and tapped for a spider", they're referring to the 8-legged sheetmetal spring in the lifter valley that holds the roller-lifter dogbones in place. No, "all '87 and up small-blocks" are not drilled and tapped for that spider.

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The other spider is the Vortec fuel injection system.