400hp 350 Vortec?

[minicooperzoom]

I’m just curious as to what the best way would be (if possible) to get around 400hp (at the crank) reliably out of a 1998 Vortec 350?

I know eventually my 350 is going to be rebuilt and when the time comes I would like to gain some power

 

[BerHntr]

Ls swap

 

[kennythewelder]

It wont be easy, or cheap. You would need to do a cam, head swap, and go to a EFI system. 400 HP is a big jump in HP when your only @ 255 stock. Then to hold that power, you will need to redo your bottom end also, so a total rebuild.
https://www.summitracing.com/search...h&SortOrder=Ascending&keyword=chevy 350 fuel%

 

[kennythewelder]

IMO it is much easier to do a carb swap, but them you will need a stand alone trans control ECM.
https://www.summitracing.com/search...h&SortOrder=Ascending&keyword=4l60e trans con

 

[minicooperzoom]

Ls swap

I Will Never LS Swap My Step Side haha! I'll do that to a 2WD when build a street truck haha

It wont be easy, or cheap. You would need to do a cam, head swap, and go to a EFI system. 400 HP is a big jump in HP when your only @ 255 stock. Then to hold that power, you will need to redo your bottom end also, so a total rebuild.
https://www.summitracing.com/search?SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=chevy 350 fuel%

I figured it would not be cheap or easy. But wheres the fun in taking the easy way out? haha
I plan on wanting to do a full rebuild that way I know everything inside is fresh and up to par with all the other components being installed.
Would porting my current Vortec heads work to support the air flow required?
Would FiTech work well (I know they have kits for varying horsepower levels) or is there a way to upgrade the factory fuel injection system to support the power?
Would going with like a 383 Stroker kit for the bottom end work well? (I know fuel economy will go out the window but I am already averaging 10mpg so I don't have much left to loose haha)

 

[kennythewelder]

The OE Vortec heads are bad about cracking. Yes port and polish will help, but there is more to it that that. The rocker arm studs are pressed in, and will need to be removed. The holes will need to be threaded and the screw in studs will need to be installed. Also the spring seats will need to be cut to allow for clearance for any cam larger that around 500, I think. They clam that the CPI will support around 400 HP, but from what I read, that is its limit, and you may not get that out of it. To make good power, you need to get fuel- air mix into the engine, and then exhaust out of you engine. As for a 383, yes those engines make good power, but again, the bigger the cylinder, and piston is, the more air and fuel it will need. The power in any engine is in the heads, and cam or fuel delivery, and then that needs to be able to exit the engine with out restrictions.

 

[minicooperzoom]

The OE Vortec heads are bad about cracking. Yes port and polish will help, but there is more to it that that. The rocker arm studs are pressed in, and will need to be removed. The holes will need to be threaded and the screw in studs will need to be installed. Also the spring seats will need to be cut to allow for clearance for any cam larger that around 500, I think. They clam that the CPI will support around 400 HP, but from what I read, that is its limit, and you may not get that out of it. To make good power, you need to get fuel- air mix into the engine, and then exhaust out of you engine. As for a 383, yes those engines make good power, but again, the bigger the cylinder, and piston is, the more air and fuel it will need. The power in any engine is in the heads, and cam or fuel delivery, and then that needs to be able to exit the engine with out restrictions.

So would the Chevrolet Performance Ram Jet system work? https://www.summitracing.com/parts/nal-12498032/overview/
Ah so the factory heads would require being completely machined and then still a risk of being a failure point? Would a set of these work perhaps or a set with around equivalent specs? https://www.summitracing.com/parts/tfs-30210002/overview/

 

[kennythewelder]

ram jet, yes, heads, are not vortec, so ether a non vortec ram jet, or some vortec heads, but I like the specs on those heads 202 intake is grate. 202 intake valves, with a 292 cam has been a staple for 350 performance for years.

 

[minicooperzoom]

ram jet, yes, heads, are not vortec, so ether a non vortec ram jet, or some vortec heads, but I like the specs on those heads 202 intake is grate. 202 intake valves, with a 292 cam has been a staple for 350 performance for years.

Are there any aftermarket Vortec heads that are better/stronger than stock ones?
I take it a higher flow fuel pump may be in order as well?
Is that combo known for being capable of making over 400hp?

 

[kennythewelder]

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