1984 350 block with vortec heads

[Caspian]

Best I can find for the RV cam is:

RPM range: 800-4200
duration: @ 0.050" 206/212
Lift w/ 1.5 rocker: .425/.440
LSA: 108*

I’d go with the beehives and the Comp retainers just to be safe. LO5 TBI heads are different from L31 Vortec heads. You cannot run a camshaft with a fairly big lift with a set of stock vortec heads. A guy I know is running a cam with a somewhat big lift on a set of LO5/TBI heads with no work, but it can’t be done on L31 vortec heads without modification.

You’ll have to measure clearance if you bolt them on and get the lash set to know if you’ll for sure need to machine the guides and get bigger springs. Comp sells a tool you chuck in a hand drill that’ll cut the guides down and the spring seat a little bigger.

 

[Supercharged111]

I have a marine cam with 1.6s and stock Vortec springs, so .460 intake and .480 exhaust. I didn't like the installed height of the LS spring, that's what I was going to run.

 

[centex14]

After looking at the heads again I'm going to take them to a shop and them worked over. For $350 they are going to clean them, square them up, magnaflux them, do a valve job, new valve seals, and assemble them. Just cheap insurance in my mind to make sure nothing is wrong with the heads since they do have over a 100k miles on them, coolant passages were partially plugged, and there is a bunch of carbon build up on them. Plan is to pick up a weiand dual plane intake manifold and a set of PRW 1.6 self aligning rockers and hopefully get everything put together by Thanksgiving before my son is born. If I can swing long tubes and the exhaust by then I'll do that to. Should be a fun little truck after this.

 

[tachrev]

So self aligning rockers, ls6 springs, valve lap, check for warpage, new valve seals, new intake manifold, and away we go. Seems to easy.

Built most of my engines this way. Clean up, check guides, lap valves, new seals and springs.

If things don't check out (warped deck, bad guides, bad valve seats), then get a machine shop involved.

 

[Erik the Awful]

Magnaflux is a must. I took four heads to the machine shop and got two back. The cracks were near invisible.

If you break a valvespring you trash a piston. I'd use new valvesprings, keepers, and retainers in anything but the most budget-restricted rebuild. My race team ended a race weekend with our BMW because a retainer cracked, kissed the piston, and bent the valve. The previous owner had upgraded the springs with the stock retainers. Bad juju.

You can run up to .520" lift on Vortec heads with no cutting if you use LS2/LS6 valvesprings with Comp Cams 787-16 retainers and the old style umbrella valve seals instead of postive-type seals. I have .515" lift with no issues so far, but I've heard that above .520" you run the risk of the stock hydraulic roller lifters cocking in the bore.

 

[centex14]

I should only be around .456/.469 lift with the current cam and 1.6 rockers, I'm not to worried about the stock springs. I may just stick to the 1.5 just to be on the safe side.

If I piece everything together, it looks like I need these parts:

https://www.summitracing.com/parts/cca-787-16
https://www.summitracing.com/parts/..._YwuUvO7QA9F9_wKXZGDOgwcyrZd8PBBoC1SQQAvD_BwE
https://www.summitracing.com/parts/fel-ss71039/overview/make/chevrolet

Which adds another $154 in cost. But wouldn't I also need to change from press in rocker studs to screw in rocker studs?

 

[Hipster]

I should only be around .456/.469 lift with the current cam and 1.6 rockers, I'm not to worried about the stock springs. I may just stick to the 1.5 just to be on the safe side.

If I piece everything together, it looks like I need these parts:

https://www.summitracing.com/parts/cca-787-16
https://www.summitracing.com/parts/..._YwuUvO7QA9F9_wKXZGDOgwcyrZd8PBBoC1SQQAvD_BwE
https://www.summitracing.com/parts/fel-ss71039/overview/make/chevrolet

Which adds another $154 in cost. But wouldn't I also need to change from press in rocker studs to screw in rocker studs?

Z 28 springs are drop in's without out the damper on vortecs. You would still need to cut the guides for clearance. They run about 110 lbs on the seat and 280 open and good to about .480 lift installed @1.74. They run about $30 dollars for a set. I would invest in a set of hardened keepers. A valve job sinks the valve a few thousandths so you end up a little less then advertised specs. A little easier to deal with then 90lbs springs that might end up at 75lbs after a valve job without a lot of shimming.

I wouldn't run old tired springs for anything other then cam break-in
https://www.competitionproducts.com/Hi-Tech-Racing-Products-Valve-Springs/products/2617/

https://www.alexsparts.com/sbc-z28-...it-500-max-lift-to-suit-stock-sbc-iron-heads/

Rocker studs can be pinned. This is just fine for a mild build like this.

https://www.speedwaymotors.com/Press-In-Rocker-Arm-Stud-Pinning-Kit,734.html?sku=550806&msclkid=19347cba7bf91f749ed321268231c8fd&utm_source=bing&utm_medium=cpc&utm_campaign=SMI - Shopping (CSE) (Bing)&utm_term=4577404346894473&utm_content=All Products (Sep9_2019)

 

[centex14]

It's in the shops hands at this point. Told them to run through everything and if anything needs to be replaced or seems off let's just get it fixed. I appreciate the help and the link to the z28 springs. Cheap as those are I'll probably just buy them. $30 is better than $150.

 

[Hipster]

It's in the shops hands at this point. Told them to run through everything and if anything needs to be replaced or seems off let's just get it fixed. I appreciate the help and the link to the z28 springs. Cheap as those are I'll probably just buy them. $30 is better than $150.

It works, it's not a new idea , or my idea, a quick google search will bring quite a few pages on the subject of the z-28 springs on a Vortec. I have done a few this way

 

[centex14]

Got the heads back. Had to be decked .012. I think I'm going to go ahead and pick up some z28 springs and comp 787 retainers. The cost of a comp xe274 is so minimal and as deep as I'm going it wouldn't be much more to slap a new cam in this truck.

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