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I'm building a chevy 350 for the 57 pickup. Have a set of 291 double-humps, but are not rebuildable. I see I can buy Vortec cast iron (64cc) at Jegs for $290 each. I'm using flat top pistons and am reaching for a 10:1 ratio.
I know I will have to get a Vortec intake, but is that the only difference? Still use the same stock length pushrods? Have to use self-alligning rockers? If so what are self-alligning rockers??
Vortec seems to be an inexpensive way to go. Thoughts are welcome...

Helped put together a vortec 350 last winter. We used an old block we had sitting around. The bottom end was pulled apart, inspected and reassembled with stock parts. Bought 'Edlebrock' aluminum heads, intake, cam and valve train. I suggest very strongly that you read and heed the instructions provided as some things are not as they use to be. Went with roller rockers which meant the push rod length changed. Read the instructions and call your manufacturer if necessary. All-in-all it went together pretty well with a little head scratching. Only issue I can remember was instructions said to use a product like RTV and not used the intake manifold gasket. Had a coolant leak near the dist. on the intake as we didn't put enought RTV at that location. Good luck

Don't feel too bad...I'll guess that about 50,000 other people had the same problem. This was one of GM's bigger SNAFU'S on the Vortec.

Stuart

If I'm not mistaken, you need some self aligning rockers and pushrods from a late model motor. I believe the vortec heads won't allow for alot of valve lift without some machining. If you are going with a stock build or just a mild RV cam you should be alright though.

57 Chevy,
The reason you need self aligning rockers is due to the pushrod holes in the head.The vortec are larger unlike the early design which utilized the heads small hole to keep every thing lined up.The self aligning have a slot in the valve end that keeps the rocker from sliding off the valve. Just by a set of stock rockers they will work just fine.You can run a stock length pushrod I only recommend if are planning to race or rev the crap out of it (6500 rpm) buy a set that are at least carbonitrited (hardened).All in all the vortec head will out flow any stock head and better yet spend the money and buy a head with at least 200cc intake runners.Remember you can build compression but if you can't get the air flow it won't gain you a thing.

Thanks for the information fellers. I decided to try the Vortec heads and keep a 10:1 compression ratio (much easier to change heads for better flow later than increasing compression). Only using a .453" lift cam, and my racing days are long passed. I was reading terms that I've not heard before. Thank you 61 suburb for the explanation. That's why I like this website. You can ask a question and get an answer without feeling stupid.
Time to get my hands dirty.

Sounds like you already know about the lift limitation with stock Vortec springs. You'd have to go with different springs if you wanted to go with big lift.

I've heard nothing but great things about the Vortec heads. It would be a nice swap with my 350 too, but there's nothing wrong with my current heads and I'm not going to fix what isn't broke.

Good choice though.

I bought a set about 5-6 years ago from Salleee Chev in WA and they gave me a new set of rockers from a ZZ4. Used stock push rods. They had a lot of them from thier engine building program where they switched to rollers. The lift is limited to .480 w/o some mild machining but tht still allows for a LOT of cam choices.

I have a fair bit of experience with the Vortec heads. I would suggest using the springs that the cam manufacturer specs for your cam. The lift limit is only partly due to the springs, the valve guide bosses are quite tall, there fore you should check the seal to retainer clearance too. You should have .050" or more at max lift, if not a machine shop can cut the bosses down. I would also try to keep the compression down to about 9.0-1 or 9.5-1. 10.0-1 is alot for Iron heads and pump gas with a mild cam. These heads don't need much total timing, try around 32 degrees. You may also want to drill a small .125 - .187 hole in the thermostat. These heads block off the bypass port in the block. You don't have to do this but it doesn't hurt anything. These are the things I have learned running these heads on my 70 Nova street & strip car. All in all they are a good bang for the buck. Good luck.

Sean

We just did a Vortec head conversion on my son's 1978 Z28. We purchased a kit from Scoggin Dicky Chevrolet. It was very nice. Has the spring upgrade for cams up to .525 lift, heads, rocker arms, head gaskets, intake gaskets, edelbrock performer RPM air gap manifold, manifold bolts and head bolts. Very nice kit for a very good price. It was nice to have all the parts and pieces together and it all works great!