I've got a base spec 350, and a chance to purchace a set of fresh machined Vortec heads for cheap. They've been modified such that they are good for cam lift of .600. I have no plans to go that far, but am thinking a rumpity-rump hydaulic flat tappet. What do you think? Thank you
no better factory head, really good for a driver, just watch the spring pressure if your running a flat tappet cam.
I have that exact setup, down to the mild cam....not enough lift or spring to change the rockers in my case...runs great. Stock guides, rockers, pushrods.
"What year 350 you got? The Vortec heads require special rockers, gaskets and manifold" Golen engines built it as a replacement for my TBI '89 P/U. It's already got a flat-tappet cam. The heads are complete, in cluding rockers. Thanks for the input. Any more?
You will need a Vortec specific intake manifold. Edelbrock makes what you need. Unless your heads have been modified for screw in rocker studs with push rod guide plates you will need self aligning rocker arms. Hard to make a SBC with Vortec heads look "right" in a traditional hot rod. But they really make the power.
Great! you have factory roller cam provisions!! 350 ramjet cam- (.430 lift intake/ .450 lift exhaust) http://sdparts.com/details/gm-performance-parts/14097395 lifters http://cgi.ebay.com/ebaymotors/305-...7766979?pt=Motors_Car_Truck_Parts_Accessories Plus you need the spider and hold downs (keepers)
Great! you have factory roller cam provisions!! 350 ramjet cam- (.430 lift intake/ .450 lift exhaust) http://sdparts.com/details/gm-performance-parts/14097395 lifters http://cgi.ebay.com/ebaymotors/305-...7766979?pt=Motors_Car_Truck_Parts_Accessories Plus you need the spider and hold downs (keepers) Doesn't look like much cam - according to the guy with the heads, their good for up to .550.
Don't rush out and buy the roller stuff just yet ... you need to make sure you don't have stepped lifter bores. I had an '87 305 with "all the provisions for a roller cam" ... and guess what, my block had stepped lifter bores that were not roller cam friendly.
I would do it. If you're concerned about the valve covers buy the adapters. For iron as cast heads they flow pretty damn good. Most magazines have done it to death but these heads on a 350 with a comp 268 cam come right in at 400/400
I would do it. If you're concerned about the valve covers buy the adapters. For iron as cast heads they flow pretty damn good. Most magazines have done it to death but these heads on a 350 with a comp 268 cam come right in at 400/400 Is the cam you mention a flat tappet or roller?
Don't let the numbers fool you, in a 9 to 1 350 with Vortec heads and good headers and intake that cam can make 360 HP at the flywheel at 5500 RPM and over 400 FtLbs. TQ from 2000 through 4500. No it doesn't have a rumpity rump idle but it starts pulling right off idle and doesn't stop until about 5500. It is the same cam used in Marine 350's with Vortec heads and the HT383 crate motors. It's a great sleeper combo in a light car and a great truck engine. Stock Vortec ports really don't see much benefit from cam lifts over .500 and are at their strongest at lower lifts. The ZZ4 roller cam is also a good match and has a bit of a lopey idle in a 350 although it only picks up about 25-30 HP at 5500 and loses about 40 ft.Lbs. down low.
Anyone ever drill and tap Vortec heads to bolt on an earlier intake? Doesn't look like it would be too hard. Larry T
x2 on that ...my nephew just went thru that one on his....new cam take 2 ....but if they have had some work done , have they been cut for big springs , screw in studs ,guideplates or do they have a heavy stock style spring or beehive spring ?
I would just run a vortec style manifold you can pick up cheap ones on ebay for about 145. not sure how they do for power though..
Thanks Brandon, I should have done a search first. Looks like RHS and Chevrolet both sell Vortec heads with a dual intake pattern. 1950coronet600hp I've run the same LT-1 intake and valve covers on my daily drivers for years. I figure I might build an engine with Vortech heads and run them on it too. I don't mind the valve cover spacers to adapt the early covers to centerbolt heads, I'll need the extra room for the roller rockers you have to run with the Ramjet cam I'm gonna run. I've got most of the stuff to do this besided the heads. Looks like I might have to replace my balanced,flat top piston rotating assembly for one with Vortec pistons but that's ok. I'll use it on something else. Larry T
i know of one 330hp vortec head motor that has been 10.90's with a cheap professional products vortec intake......with a 465 lift cam amazing what 264@50 duration can do
Vortec or similar aftermarket heads on a 350 2 bolt main cast crank,9.5 compression,cam of around 220 duration at .050 lift and .500 total lift,600 cfm carb,tube headers,good ignition equals 375 hp at around 5500 rpm and 400 ft lbs of torque over a wide rpm range with a fairly calm idle.So easy and cheap and that's why you see so many SBC's
So who's got the low down on what casting # vortec's flow the best or are the most desireable. Any sites out there I can reference?
Okely Dokely ... this is what I found. Look for casting number 12558062. Avoid casting number 10239906 that is found in some 3/4 and 1 ton trucks (something about exhaust seat limiting flow). Casting number ending in 059 are 305 heads. Happy hunting.
^I actually heard the whole 12558062 vs 10239906 deal was debunked and that they flow equally well....but that may have just been internet forum jabber....
I have vortecs on my '86 block, Edelbrock Performer manifold, Edelbrock 600 cfm and 264 megacam, 9.5 compression. I was building for torque and got it in spades. Engine has a nice idle with a little lope to it. Not a "traditional" look but it's covered up most of the time anyhow.
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