Ok, my warranty on my long block will be up soon, and I'll be pulling the motor to change the oil pan gasket, and the heads, and the cam.

Here's what I was thinking:

Comp XE 274 cam
World 58cc heads
Holley contender intake ( already running it) idle-7200 rpm dual plane


I don't want VORTEC HEADS! I already have a great intake, I want to keep it, I know I'll produce more power with Vortecs, but I'll also have to upgrade the valve springs to handle that cam. The world heads can handle .560 lift as is.

Is the cam too big?


BTW this is for my 84' with the L69.

Is the cam too big?

 

Where are all the Carbed and Modded 305 guys at? I need some motivation and some thoughts/ideas!

 

some say the 274 is too big but i dun think there should be a problem cuz its a manual and ya got 3.73s.....it will definately be a higher end motor though

 

I would say that cam too big, never go above a XE268 on a 305, or you'll lose all power until 4000rpm. But how often are your gonna be running around a 4000rpm. And your power band will only be from 4000-6000 rpm, who wants that for the street, not me.

 

Rb83L69 has a cam as big or bigger than the 274, he runs with LS1's and a 305. The power band for that cam is 1,500-6,000 rpm. I don't know where 4000-6000 is coming from. The intake I have makes power up to 7200 rpm so it's good, but the heads will probably only flow to 5800 rpm or so with that cam.

I see everyone using XE268's but not to many 274's ......it's only 1 step up and the duration of the cam in regards to how much lift you get is great for the low end and midrange power.

 

I'm at work and kinda skimmed real quick through your post.........but did you say you're going to swap vortecs for World 58cc heads?? Are you nuts?? I know of people that did the opposite swap to GAIN power. World S/R heads are just factory replacement of "fuelie" style heads. Vortecs will make a ton more power if setup right.

 

ok nevermind, read the post more thoroughly (duh) but I'd still say to stay away from World S/R heads, they really offer no improvement in power over stock pre vortec design heads other than the fact that they have bigger valves and better valvesprings. Save up and get some Sportman 2's 64cc and have them milled.

 

I thought that you can't get those vavles to fit in the small bore 305? 2.02 -1.60 on the Sportsman 2 heads.

 

The World heads are a good starting point. They aren't bolt-ons, though.

The valve bowls and guides leave a lot to be desired the way World leaves them. Get in there with a die grinder and do the Standard Abrasives Do-It-Yourself-Porting guidelines job to them, and they're a whole different animal.

2.02/1.60 valves will "fit" in the cylinder, they're just so shrouded that it's questionable whether there's any benefit to having them.

As to whether Worlds are a better choice than ported stock or raw Vortecs: You'll spend about the same money getting stock or Vortec heads up to snuff with ported Worlds (springs, guides, studs, etc.). I'll take aftermarket quality castings to factory production castings in that trade-off.

P.S.: .560" lift with as-recieved Worlds is a bit of a stretch. .510", maybe, but you'd better consider upgrading springs beyond that.

 

What about the aluminum heads off of ZZ4 crate motors, or the L98 58cc aluminum head from Corvettes? ( I think they are the same) Do they flow much better than 416 L69 castings?

 

The L98 alumium head would be a good one .
Yes they flow better than stock 416's. Especially on the exhaust side. They have lots of room for improvement with porting too.

Go for it.

 

Why limit yourself by taking Vortec's out of the equation?

You WILL be disappointed by the World S/R 305 heads if you're looking for a big bump in power, and at $370 EACH before shipping at Summit....why even think about 'em?

That's $740 BEFORE shipping.

So go buy the Pro Action redesigned Vortec's for $400 or so BARE. Then spend another $250 to finish 'em off. Out of the box these are cast for screw in studs, the ports have been cleaned up and improved, and they are cast for bigger better valvesprings from the get-go.

So that's $650 before shipping.

Now sell you're intake, and get a Vortec RPM Performer. So you're almost DEAD even on price now.


Just my 2 cents.

 

Why buy them from Summit?

Competition Products have them for $470/pair bare, $610/pair unassembled complete, plus shipping.

Pro Toplines are a little less, but don't come in 58cc chambers. So, add the cost of shaving them to the final price.