What is the cheapest way to get 400HP out of a N/A 350? Does anyone have a proven combo for cheap? I can get a 350 out of an 89 Suburban for $300

 

Do you want carbed?? or no preference??

 

Can we assume its the original motor?

Roller 1 piece RMS block?

 

I have a 750 demon and all the carbed goodies. Yes it will be stock short block. I was thinking a nice cam and some worked vortecs and I should be in the 400hp range?

 

Are you looking to put 400 to the ground or at the fly?

If you want 400 at the ground your going to need to be just below 500 at the crank which is going to require alot more than a cam and vortecs.

400 at the fly isnt too bad to acheive. My new motor is *supposed* to be around 350-380hp (digital dyno, DD2000) and im running a comp XE268 cam and lightly worked 416 heads.

Check out this article at CHP, they throw together a bunch of combos and throw em on the engine dyno so you know what kind of power the combo should make.

7 Hot Engine Combos - 355ci 400/420
http://chevyhiperformance.com/techar.../148_0306_355/ - 355ci 440/425
http://chevyhiperformance.com/techar...38/index2.html - 350ci 409/427
http://chevyhiperformance.com/techar...38/index3.html - 355ci 506/436

 

These heads are currently known as RHS. You can get very close with some minor cleanup. Someone I know is running this exact setup. Here is his current specs and time.

357ci/TH350, 8.5" 3.73
M/T ET Streets, 235/60/15. Launching at 4100 RPMS off idle

This time was done on a humid wet day. It was drizzling rain.
60' 1.715
1/8 7.866
mph 86.31
1/4 12.446
mph 106.81

 

I said cheap! $5,000 in not cheap to me LOL I was looking to spend as little as possible. I know someone on this board has built 400Hp very cheaply on here. Like I said I can get an 89 4 bolt 350 that runs very well for $300 complete. Would vortec heads and a cam give me 400 HP at the crank?

 

Trust me you can build that engine fairly cheap. He paid $500 for those heads complete with a mild port job. I used a crate engine as an example. Im sure you can do it fairly cheap if you get the right parts and shop around. Stock vortecs will need alot of work and $$$ to get it up to par.

 

I think that the dyno graphs and all that, was just posted as information; not so much as a suggestion that "this is what you should get".

The Vortec heads are about the cheapest way going right now, to get HP in that range. I'd avoid the "worked" ones if possible, because by the time you "work" them, you're already 2/3 to 3/4 of the way to aftermarket heads which are superior. The trick to using Vortecs successfully, and cheaply, is to stick within the constraints that they come with, and avoid spending money trying to max them out.

That means, keeping the cam mild enough that the limits of stock diameter springs and pull-out studs ARE NOT EXCEEDED. The absolute max cam for this particular situation appears to be the Comp XE268. Lots of people have got near 400 HP with stock those heads, a flat-top 350, and that cam; the only change to the heads being to install the recommended springs WITHOUT doing any spring pocket work.

Unless you have the ability to finesse valve spring setup though, I'd suggest going one notch below that one. Use the XE262. Some other people are running that one, and getting similar results; 375-380 HP kind of numbers. Which, for stuff you can get at the junkyard, is not too bad.

So there's your recipe. A flat-top 350 short block, zero-decked to the pistons; TRW/SpeedPro forged pistons (2256); stock rods & crank; Vortec heads, stock; regular composition .039" head gaskets such as FelPro; Comp XE262 with 981 springs; some better than stock rockers, such as the Comp 1400 series; RPM or Air Gap intake; 750 CFM Holley; headers and full exhaust of course. That'll put you right close to 400 HP for little more than a "rebuilder" garbage motor.

 

Yes exactly it was just a suggestion. 12.48 @ 106.11 mph is the best of someone else I know with a similar setup with stock vortecs. I just wanted to point out at least a couple people who have started the season with that recipe.

 

I dont know as if hes going to make 400hp with a 262 cam and vortecs.


hmmm, have to puch this into the desktop dream-o-dyno 2000 when i get home...

 

I love this site you guys are the most knowledgeable on the net. Thanks for all the info! Keep them combos coming! I want to see who has the cheapest proven 400 crank HP on here.

 

Right, like I said, probably 375-380 with that combo.

 

I know you say that the stock studs should be fine but I know at least a handful of people who have pulled stock studs even with mild cams like those. At least have them studded. Also isnt the max lift on stock vortecs .470 till you have interference with the valve retainer. I would think with that cam you would have to make sure it was right on the money because the clearance will be tight.

 

[400 at the fly isnt too bad to acheive. My new motor is *supposed* to be around 350-380hp (digital dyno, DD2000) and im running a comp XE268 cam and lightly worked 416 heads.

I have a set of 416 heads, and would like to know what you did to yours (lightly worked). I am going to put them on a stock 350. What will they do to my CR, torque and HP? Also, can I use 1.6 rockers with this application?

 

Not much done to my heads. A bit of cleanup work and gasket matched the intake runners.


As for what it will do to your CR tq and hp will depend on the rest of the motor.

For the rockers you might get away with 1.6's depending on the cam. My heads needed absolutely no work and i had room to go .55 lift (with .050 retainers)

But the guide height can vary lots even on one head. if you want to run a fairly high lift cam or 1.6 rockers you have to measure every guide to make sure none will hit.

 

Althou vortecs are a good no great way to go, you can beat them price wise using fully ported and prepped 416's on a flat top 350. Use 1.94x 1.60" valves, pin the rocker studs and after you've ported them yourself have a valve job done for the new valves and shorten the guides for high lift. (cut .200")
use a nice hyd like Comps XE 284H or if you don;t mind a sweet street solid camshaft use Cranes F278-2 . Crane #113841.. Use manley # 22410 springs for 7000rpm capability. (total cost $440 Can) (about $400US) Top it off with a Performer RPM or Professional products "Crosswind" manifold and a 750cfm carb and 1-5/8" headers.
Here's a pic of what your budget ported 416's should look like once home ported.
I'll be track testing these 305 heads against my Ported vortecs later this summer. there is more than enough flow in these heads for 400+hp and deep 12's ets. needs lots of gearing traction and a good 10" converter.