350 Engine upgrades

[HotRodPC]

I guess I didn't read the whole thread, but you're going away from the TBI???

 

[87ChevyR10]

I guess I didn't read the whole thread, but you're going away from the TBI???

I don't know what I'm doing atm. I may do nothing. Problem I am facing is these parts are practically bolt-ons; yet, they don't act like it. Like I said earlier, maybe I should go back to a 4-banger. They are much easier to work on and just about everything bolts on.

TBI vs carb, I can prolly spend less money on a carb setup than buying all the TBI upgrades.

I would say for now, consider the upgrades dropped.

 

[HotRodPC]

Maybe the first questions to ask is, What are you wanting to accomplish? And #2, What is the budget like?

As far as 4 bangers, you can throw money at them all day to make them go fast but for how long? If it's just temporary speed you want, then you might be right and that's not due to performance as much as it is weight.

 

[Driver4r]

[QUO TE=Driver4r;211408]
Fyi you may want to look into those 906 of yours from what I read they restict exaust flow and are undesirable

Theres 2 versions of the 906's, the 1 tons, and the good ones. The 1 tons have hardend seats which hinder them alot, but i got mine off a half ton and it doesnt have them.

 

[Stroked]

Yes, the 906's are terrible. If you have any, just go ahead and give them to me and I will take care of them for you...

Sent from my Kindle Fire HDX using Tapatalk

 

[Driver4r]

Yes, the 906's are terrible. If you have any, just go ahead and give them to me and I will take care of them for you...

Sent from my Kindle Fire HDX using Tapatalk

lol at first i was getting deffensive and gonna comment , then i finished your sentence

 

[bucket]

Building one of these V8s is certainly easier than building a 4 cyl, the difference is picking through and finding the parts that work together or with what you already have. The only thing that makes it a little difficult is the TBI's lack of popularity, there's really not a lot out there that is designed with TBI in mind. So you have to work around it or go with something else.

 

[87ChevyR10]

Stay away from the JET tune, you will need a custom chip to run the vortec heads, and whatever cam you choose, if it is more than the next step up from stock. Remember, the higher the duration on a cam, means your torque is going to move up the rpm range....not good for a truck. You will need a datalogging cable, laptop, and software(usually free) for the tuning process, unless you can find a tuner locally that can log and tune while you drive.
You will also need to set up a 3 wire heated O2 sensor to use with any headers longer than shory's.
There is a factory GM chip out there that is set up for TBI and vortec heads, but it would require the use of a 94-95 PCM. Thes can be found in some 96 1 ton vans with the 350.

I don't believe mine has an O2 sensor. The cat is missing and already has what looks to be LMC turbo muffler exhaust kit or something similar.

EDIT: I just checked and I saw no wires coming from the exhaust after the headers. So, I will be able to install long tube headers easily. I believe I found an exhaust kit that will work with my truck and it comes with glass packs as well. http://www.jcwhitney.com/heartthrob-exhaust-dual-exhaust-systems-for-long-tube-headers/p2006349.jcwx?skuId=194823&filterid=c15836d50303u0j1

 

[Jims86]

I don't believe mine has an O2 sensor. The cat is missing and already has what looks to be LMC turbo muffler exhaust kit or something similar.

EDIT: I just checked and I saw no wires coming from the exhaust after the headers. So, I will be able to install long tube headers easily. I believe I found an exhaust kit that will work with my truck and it comes with glass packs as well. http://www.jcwhitney.com/heartthrob-exhaust-dual-exhaust-systems-for-long-tube-headers/p2006349.jcwx?skuId=194823&filterid=c15836d50303u0j1

If you have TBI, and no o2 sensor, there is something wrong...unless the PO installed an early holley Pro Jection system.
Any stock vortec head is an excellent upgrade for these trucks. the complaints abouth the 906 are usually from car guys, trying to crank 8000 in camaro's and such.

The L31, 350 uses two castings, either makes the same part number 125508060, the castings that make this P/N are 10239906 or 12558062. The difference between them is how the exhaust seat is wear treated the 906 uses hard seat inserts while the 062 uses induction hardening of machined in the casting seat.

you can still do the vortec swap, however, it has been done so much, you can call a tuner, like Westers Garage up in Canada, who has done thousands of tunes. Tell Eldon what you are doing, and he can suggest a Cam to run with the heads....may be a combination in which he already has a program for. just like buying a Jet chip, but for use with vortec heads.
I also know a guy in Vancouver, Wa that has tuned for vortec heads, but you will beed to be able to Datalog...its worth it in the end.
I recommend getting a ported TBI from CFM-Tech, and an adjustable fuel regulator capable of giving you 15psi.

 

[87ChevyR10]

If you have TBI, and no o2 sensor, there is something wrong...unless the PO installed an early holley Pro Jection system.

Any stock vortec head is an excellent upgrade for these trucks. the complaints abouth the 906 are usually from car guys, trying to crank 8000 in camaro's and such.

The L31, 350 uses two castings, either makes the same part number 125508060, the castings that make this P/N are 10239906 or 12558062. The difference between them is how the exhaust seat is wear treated the 906 uses hard seat inserts while the 062 uses induction hardening of machined in the casting seat.

you can still do the vortec swap, however, it has been done so much, you can call a tuner, like Westers Garage up in Canada, who has done thousands of tunes. Ask Tell Eldon what you are doing, and he can suggest a Cam to run with the heads....may be a combination in which he already has a program for. just like buying a Jet chip, but for use with vortec heads.
I also know a guy in Vancouver, Wa that has tuned for vortec heads, but you will beed to be able to Datalog...its worth it in the end.
I recommend getting a ported TBI from CFM-Tech, and an adjustable fuel regulator capable of giving you 15psi.

If I'm not mistaken, the O2 sensor plugs in between the stock header and the cat. My truck didn't have a cat when I bought it. It has been running just fine w/o it. So, what's the problem? I haven't even bothered looking at the TBI to see if it is something other than stock. I'll have to check when I get the chance.

 

[Jims86]

If I'm not mistaken, the O2 sensor plugs in between the stock header and the cat. My truck didn't have a cat when I bought it. It has been running just fine w/o it. So, what's the problem? I haven't even bothered looking at the TBI to see if it is something other than stock. I'll have to check when I get the chance.

First thing...does your check engine light work? Turn the key to on, and it should illuminate. If not, thats the first thing to fix.
second, the o2 sensor was located in the drivers side manifold, right before wher the intermediate(y) pipe bolts up.
You NEED an 02 sensor for the EFI to work properly. The reason for the heated o2 sensor with mid and long tube headers is because the sensor will be moved farther from the engine, resulting in bad readings due to the sensor cooling off. Lets get your truck correct and baselined before any modifications.

 

[HotRodPC]

Lets get your truck correct and baselined before any modifications.

I agree !!! We like our **** right !!!

 

[87ChevyR10]

The only light that comes on is the Brake Light. I imagine the PO disabled the CEL because the O2 sensor is missing.

How hard will it be to install the 3 wire sensor?

 

[Stewzer55]

I'm looking to do this with my 350.

 

[Jims86]

Not hard...
https://www.texas-speed.com/p-2589-caspers-heated-o2-sensor-retrofit-kit-for-early-1-wire-gm.aspx
If your engine is not too worn out, be prepaired to see a pretty good jump in power, and around 17 or so mpg, depending on driving habits.