5.7l Vortec - Need modification ideas!

[ColtonW]

Hey guys! I decided to modify this thread's topic some..

I have a 1994 K2500 with a 350 in it.. it has spun a bearing and I while it is apart I am looking to wake it up quite a bit! Currently it is bone stock, but when I am done with it I am looking to at least achieve 300 rwhp.

What all do you guys think I will have to do to make at least 300 horses?

Thank You!
Colton W.

[SUBURBIAN]

You're not going to find a conventional "TB" or conventional "injectors" because your CSFI vortec 350 does not have them. Don't bore the engine unless it is necessary. The most ideal manifold to run is the GM vortec marine intake, it goes for $500 plus, but the stock intake will be more than sufficient for an idle to 5000 rpm torque beast.. You ought to be looking for a local tuner instead of a chip.

Does it have low gears that will allow for easy towing?

[ColtonW]

The truck doesn't have a throttle body or injectors but it is fuel injected? And it does have a throttle body, I was looking at it when I was over my uncles house ealier today...? Maybe I just misunderstood what you said..

And I thought being I am going to have the engine apart, I might as well give it a new bore.. plus the truck has 175K on it so I figured it wouldn't hurt to have it bored, right?

Also you have made up my mind and simply keep the factory manifold. I will probally get long tube headers to help with the torque and possibly an 80mm throttle body (any thoughts?) for it.

And where may I find a 'local tuner'?

Thanks dude!
Colton W.

[SUBURBIAN]

It just really sounds to me like you're expecting to buy TBI-like parts for your CSFI engine.

Yeah, your truck has CSFI. GM started CSFI in in 96'. The difference between CMFI,CSFI, & TBI are as follows;

*TBI: One or two injectors, "depending on your application", are mounted in a throttle body, "similar in appearance to a carb", on top of the engine. Runs at low pressure(13-17 psi).
**CMFI: A unique form of MFI injection. Uses high pressure (54-64 psi). The fuel pump feeds an injector solenoid which disperses fuel to a poppet valve at each cylinder.
***CFSI: Similar to CMFI. Only difference is CFSI has a fuel meter assembly in place of the injector solenoid, and each poppet nozzle has it's own injector. Much better fuel control/delivery compared to CMFI. Uses high pressure (54-64 psi).

Are you sure it is a vortec 350?

[SUBURBIAN]

Oh wait, you shoulda posted this over here too, n saved me all that typing. It is a TBI 350, imagine that.


Just wondering.. wouldn't I then be able to get offset wheels that'd bring the center of the tire more in toward the middle of the truck? I was over my uncles house today and I had noticed that the front was noticably wider than the rear.. and I found out the truck is a 94 vs. a 98 as I had previously thought, if that matters! :P

[chucksrt]

Get a scat 383 rotating assy. more power and torque cost around $1200 balanced. That and a set of long tube headers should wake that engine up! I don't know if your looking to have to modify the block for a stroker? Machine work would be around $1000 it's self. I just bought a bare block from summit already machined for use with a 383 stroker kit for $750 shipped, which was less that my machine shop wanted to machine my old block. And now I have 4 bolt mains!!!

[ColtonW]

SUBURBAN.. it is in fact a Vortec. hahah
I just got the title from my uncle today and it is an '98 and I found on the intake it said vortec - DUHHHH!!
But which one is it, CMFI or CMSI?

Thanks! ;)

[SUBURBIAN]

CSFI. That is what the "vortec" engines from '96 to '00 or '01 used...even after they stopped using them in pickups.

You can make plenty of muscle with a vortec 350, more than a stock transmission can handle. To do this right, you need to get the engine out, see what you have to work with, and how much $ you have. Then we can start making a plan.

When you can look at the truck, look at the sticker inside the glove compartment, and post all the codes that start with G.

[ColtonW]

I will do that!

Quick question:
Does the 350 Vortec have a roller cam?
-If so, would I be able to use a non roller cam/lifters?

[Pauly]

I will do that!

Quick question:
Does the 350 Vortec have a roller cam?
-If so, would I be able to use a non roller cam/lifters?
yes the L31 Vortec 350 has a roller cam. You can use non-roller cam, lifters but you will also need the longer length pushrods as well. IMO a step backwards to go to the non-roller setup, but I do realize the non-roller is less expensive.

peace
Pauly

[68post]

You can buy a roller cam for what you'll spend on a flat tappet cam with good lifters and new pushrods.

Checkout this companys reground cams :

http://cgi.ebay.com/ebaymotors/HOTCAM-SB-Chevy-ROLLER-CAMSHAFT-LT4-PERF-HYD-219-228-/170605666204?pt=Motors_Car_Truck_Parts_Accessories&hash=item27b8e3df9c

[SUBURBIAN]

Willhoite is local to one of my friends. He grinds all of my bud's cams. Very reputable machinist.

[68post]

I'd asked him about one of his ebay cams concerning making it as a single pattern and/or on a 112*, here's his reply.
(I'll keep him in mind for sure, seems he is willing to do whatever request is practicial )


Dear 68post,

if it is for a roller motor. no problem.


- willhoitescams

[SUBURBIAN]

Yep. He is going to grind a 304/304 adv. 260/260 @ .050 .555" lift on 106 for my bud's old truck.

[68post]

Yep. He is going to grind a 304/304 adv. 260/260 @ .050 .555" lift on 106 for my bud's old truck.

sbc ? I have one to sell if he'd like to try a solid roller, NIB w/lifters Comp Cams .900" base circle 288-8/304-5 _ 260/268 on a 106* _ .660/.630 = $350

[SUBURBIAN]

Nope, this is solid flat tappet.