400hp 350 Vortec?

[arrg]

Edelbrock E-tec heads are aluminum vortec heads. Engine quest also makes a nice set of iron vortec replacements with screw in studs and thicker decks to prevent cracking. Keep your stock intake and do the CFSI to MPFI conversion. That'll give you reliable fueling to around 400 hp. Everything I've read about the stock computer says it has a fuel cutoff at 5800 rpm that can't be programmed around, so there's no sense in throwing a huge a cam in it. Unless you want to do a 0411 PCM swap to get around that, stick with a cam around the size of the LT4 Hotcam and settle for 350-375 hp. Maybe a few more if you put in longtube headers and a full exhaust.

 

[minicooperzoom]

Like you, I am still running the OE vortec, but I have done most of the mods without going into the engine. As for heads, any of the after market heads are better than OE. My engine still runs to good to fool with yet. When you pick a fuel system, that will tell you what FP you need to run it. If you call Summit racing and talk to the techs there, they can point you in the rite direction, as to want you want and how much you want to spend. Here are some top end swap parts for around 400 HP
https://www.summitracing.com/search?SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=vortec 400 HP

Ah. Mine still runs good but I noticed the amount of oil it’s burning has increased (1.5qts after 2000 mi. and it only has 179k mi. Use to be about 1qt every 5000 mi. That was about 20k mi. ago though)
Would going with the Ram Jet (instead of the intake supplied) and the cam and heads from the Edelbrock Total Power Package 435hp work to achieve around 400hp?

 

[df2x4]

Everything I've read about the stock computer says it has a fuel cutoff at 5800 rpm that can't be programmed around

I've seen many people say this, but I've confirmed via Torque that my V6 truck shifts at around 61-6200 with a BBP tuned factory black box. Unless there's another reason for the 400RPM discrepancy in there somewhere, I don't see how this is possible.

EDIT - Whoops, I was off by about 500RPM. Double checked my info and my V6 actually shifts at about 5700, so the 5800RPM cutoff on the black boxes might be legit.

 

[kennythewelder]

Like I said, talk to a tech at Summit before you order anything. That is what they are there for. Keep us posted, on what you do

 

[arrg]

Ah. Mine still runs good but I noticed the amount of oil it’s burning has increased (1.5qts after 2000 mi. and it only has 179k mi. Use to be about 1qt every 5000 mi. That was about 20k mi. ago though)
Would going with the Ram Jet (instead of the intake supplied) and the cam and heads from the Edelbrock Total Power Package 435hp work to achieve around 400hp?

That cam would be miserable in a street driven 350, especially in a 4500lb+ 4wd truck. It would still be borderline in a 383. Also, it would produce peak hp well over 6000 rpm which you would never see unless you address the PCM.

 

[minicooperzoom]

Edelbrock E-tec heads are aluminum vortec heads. Engine quest also makes a nice set of iron vortec replacements with screw in studs and thicker decks to prevent cracking. Keep your stock intake and do the CFSI to MPFI conversion. That'll give you reliable fueling to around 400 hp. Everything I've read about the stock computer says it has a fuel cutoff at 5800 rpm that can't be programmed around, so there's no sense in throwing a huge a cam in it. Unless you want to do a 0411 PCM swap to get around that, stick with a cam around the size of the LT4 Hotcam and settle for 350-375 hp. Maybe a few more if you put in longtube headers and a full exhaust.

I've heard about that conversion but don't know much about it.
I've never heard of the fuel cut off before?
I would like to not have to change my computer if possible. I did some research in the past about tuning and according to HP Tuner's website my truck can be tuned using their software being that it's a '98?
A 100+hp increase is still a pretty good and I could probably live with that haha.

I've seen many people say this, but I've confirmed via Torque that my V6 truck shifts at around 61-6200 with a BBP tuned factory black box. Unless there's another reason for the 400RPM discrepancy in there somewhere, I don't see how this is possible.

EDIT - Whoops, I was off by about 500RPM. Double checked my info and my V6 actually shifts at about 5700, so the 5800RPM cutoff on the black boxes might be legit.

My truck always shifts around 5000 to 5200 rpm at WOT. Not sure if that is normal or not for a stock Vortec?

That cam would be miserable in a street driven 350, especially in a 4500lb+ 4wd truck. It would still be borderline in a 383. Also, it would produce peak hp well over 6000 rpm which you would never see unless you address the PCM.

So would the LT4 cam be a better choice for drivability and lower end power?

Like I said, talk to a tech at Summit before you order anything. That is what they are there for. Keep us posted, on what you do

Yeah there is definitely a lot more research to do. When I do anything it probably will not be for another 2 to 4 years. (I just got the idea and wanted to learn more) I may start collecting parts sometime in between then but with college coming soon I don't see a full engine build coming any time soon. Then there is also the issue of not destroying my 4L60E haha

 

[arrg]

So would the LT4 cam be a better choice for drivability and lower end power?

No, the LT4 hot cam is not real great for low end power at all. But it's about the minimum cam you can use with Vortec heads on a 350 and expect anywhere near 400 hp.

 

[minicooperzoom]

No, the LT4 hot cam is not real great for low end power at all. But it's about the minimum cam you can use with Vortec heads on a 350 and expect anywhere near 400 hp.

Ah. Well it’s not the end of the world if it doesn’t make all the power down low since I don’t tend to pull/haul anything really heavy. Normally it’s just a pair of 550 stand ups on a little trailer and a 650 stand up in the bed

 

[shovelbill]

by the time you're done TRYING to get that "unicorn" running it won't even resemble the same engine you started with......just buy a motor that fits your needs.....i,ve been there and done that....**** the tee shirt too.

i'm sorry, but i'm just sick of opening threads that are total ****......carry on boys.....stock up on that fairy dust too.

 

[skylark]

Find a whipple supercharger, drop a slightly smaller pulley on it and call it done. You would have instant torque with 8-10 pounds of boost and it will work with your 100% factory engine.

If you want more when you rebuild in 2-4 years you can do a marine intake, blower cam, headers and a walbro 255 to see 500 crank horses. BTW .480 lift is the max on stock vortec heads but a spring and retainer kit will get you to .550 without machine work.