Vortec head swap

[TimberwolfFXDL]

I picked up a 2001 crate 350 with 40k miles.  Roller cam motor, but it was a TBI setup, which I'm not going to mess with.  So those heads will be hitting craigslist along with the fuel injection setup.  In the meantime, I picked up a set of 062 vortec heads.

I've read I can use LS3/LS6 valve springs, Comp Cams retainers, and Dodge Daytona turbo 4 cylinder valve seals.  This will give me up to .550 valve lift before coil bind (stock limits were .490 I believe).  I am going to run an LT4 hot cam and 1.6 GMPP roller rockers which give me a max lift of .529.

My question is, is there any reason to go to the larger valves (2.02/1.6) or will the stockers be ok for my setup?

Also, I've read conflicting opinions on whether to do any porting or cleanup.  Some say the vortec heads really benefit from bowl blending and opening the exhaust port around the valve guide, others say not to touch them unless you're going over 425hp.

What say you?

[thefarmboy21]

A nice bowl blend an mild port job never hurt anyone (you know...if you do it right) so I vote do it while they're apart. All the articles I've read say the vortecs can be used easily at around 400 horse stock. Personally I'd order the recommended springs, or order a complete kit from Competition products (not to be confused with Comp Cams) they are really cheap and I've ordered tons of stuff from them. As for the valve seals I have no idea but I always use the viton metal bodies...they don't pop off and give you maximum clearance. As for the cam, I dunno what your bottom end is but it sounds a little big. Every article I've ever read says just call the cam company...it'll be smaller than you want to hear, but they are a CAM COMPANY, they know what they're talking about! Your motor will run much better if your parts are matched to each other. My cam was two sizes smaller than I was gonna order (Comp Extreme 4x4) but man does it make some serious power and sound nasty when you lay into it. All these guys with rollers and big lumpy cams always come over and ask what I have and compliment me. Everyone says they can here mine fire up in the pits and know it's mine cause it has a distinct sound. Makes my day every time cause I know it's a stock 350 with scared up bores and just a nice set of double humps and a stock'ish lift cam.

[slammed79]

I agree with farmboy. Call the manufacturer and bend their ear. Cams make the best power when they're matched with your heads/intake/carb set up and intended use. Comp Cams has a very helpful tech line, and can hook you up with a kit designed for your induction system.

Better to do it right the first time, rather than spend a bunch of money and be disappointed.

[TimberwolfFXDL]

you guys know I wasn't looking for a cam recommendation, right?   I was asking about whether the larger valves are worth pursuing, as well as whether or not it's worth the time and effort to get the vortecs ported for my intended power level (around 375 crank hp)

[Orlando87Chevy]

I heard from my machine shop that the Vortex 305 heads are much better than the 350 heads. Bigger valves for more air flow equals more HP. I was also told to shave down the head to up the compression ratio.

[1980c10]

If your goal is 375 you can get there without trying so hard;
My set up is a 75 4-bolt 350, .030 over, flat top pistons, vortech heads(only modification is a radius grind on the valve seats and heavier springs. mild cam that fits the parameters of stock heads, f course other components are matched. dynoed at 393 hp 432 tq. this set up makes for a great daily driver but will break the tires loose at 65 shifting from 4th to overdrive.

[TimberwolfFXDL]

My block is a bit newer (thus the roller cam) and the lt4 cam should make good numbers.  What cam did you use to hit those numbers?  I assume that's FWHP?  What are you running for gears and transmission?  If an auto, what stall tq converter?

I'll be running a 700r4, and at this point am looking at a lockup converter with something in the 2600rpm stall speed range.  Haven't 100% decided on gears... 3.42 or 3.73 most likely.  It won't see a lot of highway use, mostly just rattin' around and burning off the tires

[1980c10]

I used a Crower "torque beast" cam it has a little more duration rather than lift (for torque)
You assumed correct FWHP (@5400rpm (btw)) more impressive to me is the torque #'s as it peaks at 432 'lbs but averages at 416 makes a really nice flat long curve.
Gears are stock, I finished the engine/trans install and tried it out and like the gearing, never actually looked into it.
The trans is the nv3500 (5 speed manual)
Mines kind of a weekend cruiser but I pretty much park my car and drive it all summer long.