Vortec 350 build

[onebadcaballero]

I'm in the process of building a vortec 350 based from a goodwrench 350 block shortblock (10,000 miles on it).
-062 vortec heads (with drop in valve springs) milled to 60 cc's with a .015 rubberized shim head gasket. With my deck height and pistons gives a around 10.01 to 1 comp.
-Xe274 hydraulic cam
-Proffesional Products crosswind manifold
-lt headers with True dual and x pipe
-Street fire cd igniton with 8mm taylor wires
-holley 600 dp (got jets and pump cams)
-fresh th 350 with red line clutch packs, drilled valve body plate, very strong shift kit, hardened steel sprag.
How much power can I expect to make at the crank. Wheels? Also someone told me it's hard to get 300 at the wheels with a sbc & doesnt think this combo will do it.
Its going in a 1986 gmc caballero 3386 pound

 

[G_Body_Enthusiast]

Also someone told me it's hard to get 300 at the wheels with a sbc & doesnt think this combo will do it.

who ever told you this should be beaten with a bag of nickels and publicly flogged in the town square. they probably just hate SBC's and are trying to spread their prejudice onto others.

 

[madmaxstyle]

300 hp to the wheel is not too hard on a modernized sbc.


Notice I said wheel

 

[SScamino]

http://www.carcraft.com/techarticles/44 ... index.html

 

[onebadcaballero]

I should of known his response when I pulled up to the dyno shop which was litered with hondas and acura's!

 

[onebadcaballero]

300 hp to the wheel is not too hard on a modernized sbc.


Notice I said wheel

Actually I have an open diff so..... :lol:

 

[othtim]

A lot of guys on here are running a similar build. I've got a 355 vortec w/ 9.8:1 and a milder cam, w/ a performer intake. I know there are a bunch of other vortec headed g's on here. You will like your combo I think, I love mine.

XE274 and a 600 carb.... just wondering why you have such a small carb for a large cam. I'd consider the 274 to be a higher-RPM cam. you put a single plane intake and a 750 carb on that and youre getting pretty close to 400 HP ...

I did some stuff. I put your specs (as far as I could tell) into desktop dyno.

Desktop Dyno roughly estimates this for your curve

Here/s a comparison of your cam vs a xe268h-10. Noptice the 268 actually makes more power and torque all the way up to 5000 RPM.

 

[onebadcaballero]

I was actually looking for a holley 750 with vacuum secondaries since I already have secondary springs and jets. I already have an xe 268 (not in the current engine-came from a previous build) but thought I would get detonation with the smaller cam. Any ideas on a reasonably priced single plane for vortec heads? Being that the crosswind professional products is a clone of the rpm air gap I figured it would be ideal for the combo but I don't have experience with these heads. Thanks very much for posting some numbers.

 

[SScamino]

I wouldn't really trust a computer dyno software for anything. I used engine analyzer pro the newest version and this is what I got. I too have a xe274 I stepped up from a xe268. Here's the xe268 graph.

and heres the 274

too programs say two different things. My view.. Don't trust them.

 

[othtim]

SS camino, I used a dual plane w/ a 550 carb, like the OP mentioned. how are you getting 405 HP out of a 350 iron vortec w/ an xe268? are you using the same stuff as the OP had in his build? but either way, the programs are never right, and I agree about not trusting the programs. A program doesn't see manufacturing tolerances or other imperfections, or any kind of build error. they are good for seeing trends, though.