RunningMan373

What parts would be needed to do a Vortech head swap, besides the heads and cam, onto a stock L48 motor? Do i need to run a full roller set up, or can i use a conventional setup? any parts recomendations. I'm thinking of a set of Truck heads from the wrecker yard.

Bob Walker

Not sure what heads you're thinking of, but I would advise the following...
* From a physical sense, no need to change cam just because you're going to use Vortec heads.
* If you go to Vortec heads, you will probably need a Vortec intake manifold, Vortec intake gaskets and Vortec manifold to head retaining bolts. Vortec uses only 8 of 5/16 bolts to hold the manifold down, not 12 of 3/8 as with earlier style. Earlier manifolds may not be completely cover the intake port of the Vortec head.
* The Vortec heads may need self aligning rockers or guide plates. Again, it depends on what heads you're buying
* Vortec manifolds have to be torqued down to 11 lb. ft. You may need a new torque wrench for this low torque.
* When changing the manifold, you should investigate whether your carburettor, choke, emission stuff etc is all compatible with the manifold, otherwise you might be up for some more expense.
* Vortec heads usually require centre bolt style rocker covers, not perimeter type as found on earlier heads. Aftermarket Vortec style heads usually cater for both type of rocker covers. Again, depends on the heads you're thinking of buying.
Hope this helps and good luck.

RunningMan373

To keep costs down, I'm thinking of harvesting a set from a wrecking yard and then having them gone over. I need a recommendation of what kind of heads to look for, in a wrecking yard, and what major parts i'll need to get it all up and turning in the top end of my stock '73 L48, for best performance on 91 octane gas. I'm especially interested in what cam and rocker arms to use, as i believe they come with roller type, but i want to use just flat tappet and regular rocker arms.

jackson

'73 L48 came w/ dish pistons; assume yours retains them.

Get from yard:
Truck iron vortec heads with their rocker arms & with their centerbolt valvecovers. Look for about 96-2000 ... VIN MUST have "R" as eighth character denoting the L31 code iron head 350" vortec motor.

Before you leave yard, INSPECT vortecs for cracks. Then also have a shop check em immediately so you can exchange w/ yard if necessary. I cannot stress enough how important crack-check is ... vortecs very crack-prone.

The stock vortec rockers are self-align aka rail-type but they're not roller ... you do not need roller rockers.
You do not need a roller cam either.
A good, cheap cam for an L48 w/ vortecs is summit's sum-K1103 ... cam & lifter kit's under $100. Show the cam specs to the shop BEFORE they rework the heads.
Have a shop freshen the heads with new "Z28" springs & new "conventional" retainers & new seals.
Install vortecs w/ felpro p/n 1094 thin steel shim head gaskets.

You need an intake manifold made specifically for vortecs & your carb & your low vette hood. Look for Professional Products p/n 52007. Should be under $150.

That's a common swap & been done by thousands before you ... suggest you do search here & other sites ... it's been discussed ad nauseum. Wade thru the crap & dis/mis-info.

mikep3

I just did a Vortec Swap with the SD kit.
You need heads, intake, gaskets, bolts & self align. RA @ $900. Plus new valve covers, cam, lifters, timing chain, gaskets, electric choke. that stuff got out of control $400.
I can't see saving alot on used heads that need to be re-ferbed compared to $295 for new with springs n valves. The balance you need per the Vortec Heads, intake, seals, bolts, valve covers are a min.

Plus you need to check local laws on removing the EGR???

Quil

You will also need to either modify your existing temp sending unit, or move it to the intake manifold with the Vortec heads. Definitely will need new springs...vortec springs have really low seat pressure. How much cam are you wanting to run? I have the Lunati voodoo .219/.227@.050 with my Fast Burn aluminum heads, and it runs well, but wish I had gone another size up. A lot of people like the Comp 262 or 268 cams, as well as the Crane 270. As stated, you will need the centerbolt valve covers unless you go with an aftermarket aluminum vortec head, like the Fast Burn. Make sure you get the right intake gaskets and head gaskets...the intake ports are in a different location on a Vortec manifold and won't line up right if you don't get the Vortec specific gaskets. If you go to GMPP website and look up Vortec heads, it should give you a part number for the head and intake gaskets...or you can get them at Summit or Jegs like I did. Make sure to look up the correct torque specs for the heads as well as the manifold. Don't know what year Vette you have, but you can go with the Performer RPM vortec manifold and still clear the hood with a drop-base air cleaner if you have a later model C3 (75ish and later???).

I just recently did my head swap, so I'll try to remember anything else that came up...

Lee H

I did that vortec swap on my son's 72 C10 this summer. Once I added up all the dollars for the swap I found I could have gotten a new set of aluminum heads, decent manifold and had a few $$ left over. Do your reseach both ways.

Attfay Elleybay

They're only $289 each new at Jegs or Summit.
By the time you buy a used set, rebuild them and hope they're good, are you really saving that much?

RunningMan373

What were the extra $$ for the Vortech swap that you would have saved useing aluminums?

Quil

And which aluminum heads? Most decent aluminum heads are well over $1000 a pair...you can get a set of new Vortec heads complete with upgraded springs and a new manifold for about $1000 from Scoggin-Dickey.

Here's the link to the kit I'm talking about. It's got every possible thing you will need for a Vortec swap...head gaskets, intake gaskets, head bolts, rocker arms, retainers, Performer RPM manifold, intake bolts, and the Vortec heads with upgraded springs...all for $1029.

http://www.sdparts.com/product/SD806...formerRPM.aspx

RunningMan373

Thanks Quil, that's a nice set up. Your more into engines than me,, what kind of compression and HP do you think this set up would produce sitting on a stock L48 short? The bottom end of my motor was rebuilt and is in good condition, good compression ~165 lbs/cyl, all around. All i would need would be a cam, lifters and push rods. Someone recomended the comp cams xe262, what do you think? I want a resonably smooth idle, but good power and low to mid range torque <4.5k rpms. C.

Quil

I believe the Vortec heads are about 64cc, and your stock ones are about 76cc. If you leave the bottom end alone, I'm guessing your compression ratio would be about 9.5 to 1, but I'm unsure of the cc of the reliefs in your dished pistons, which would have a big impact. Someone else may be able to get you a little closer on that. 9.5 to 1 would be a good ratio for you.

Cam choices are a dime a dozen...what kind of trans are you running, and what kind of rear end gears do you have. If you want a stump puller that only revs to 5000 or so, the Comp 262 or a small Lunati grind would be a good choice. Take a look at this article on a Vortec 350 buildup...keep in mind that it is a magazine artice, and the numbers are a bit inflated for a real world build, but it's still a great read. They make outstanding power with both the 262 and 268 Comp cams. Need to know the rest of the specs on your engine and drivetrain, though...carb, exhaust, trans, and rear end for starters.

http://www.popularhotrodding.com/eng...ine/index.html

RunningMan373

'Vette is a '73, All stock,, Quadrajet stock carb- well rebuilt, stock true duals, but am going to move to shorty block hugger headers during the build- i know, not much help, but have to be better then the two boat anchors on there now. A Muncie M20, wide ratio and a 3.55 rear diff. I would like to keep the usable RPMs to 5500, max. like the low end torque. Running an HEI. Thanks,, C.

Quil

You have a pretty good base in place for your build...good gears with the 3.55s, the wide ratio manual trans has a good ratio in first gear, decent exhaust setup, and the carb should be fine as well. HEI is a good conversion.

The comp 262 would be a good choice. It makes power to about 5500rpm, and would be very streetable. It's a very popular cam for mild buildups, and a lot of the people on the forum here use and like it very well. It's a good grind for a smaller camshaft.

http://store.summitracing.com/partde...2&autoview=sku

The Lunati 262/268 cam is also a good choice, and I have it in my current engine. It's a bit small for the rest of my components, but it's a good street cam as well. Idles great...has a little lope to it, but also pulls around 16in of vacuum at idle. It's a little bigger than the Comp 262 and would probably make a little more power.

http://store.summitracing.com/partde...K&autoview=sku

This Lunati is a step down from the 262/268, but still makes power to 5500. The good thing about this smaller cam is that it starts making power at 1000rpm, which is basically off idle. If you wanted a cam that was still a little smaller than the Lunati 262/268 or Comp 262, this would be a good one.

http://store.summitracing.com/partde...K&autoview=sku

Like I said, there's a lot of choices. I've had good luck with Lunati in the past, so I like them pretty well. The Comp would be just as good, probably. There's been some issues with wiping cam lobes on break-in lately with a lot of Comps, but I think that's more of an issue with the composition of todays oil and less about the brand of cam. Anyways, I'm far from an expert on these things, and someone else may have some better advice for you. Hope this helps.

RunningMan373

Thanks, I'll start stageing. It's tax return time.

Lee H

That is a good price. When I did the swap last summer this was not available, or I was not able to find it. I spent about $1600 piece mealing the parts together.

Walkingtall

I don't know a lot about the vortec heads, but I have a '77 L-48 and I'm in the middle of changing heads, cam, lifters, intake etc.. I found a really nice set of 1968 Z-28 heads and my racing engine builder friend redid them for me. He estimates the compression to be 9.5:1 to 10:1

I haven't decided if I'm going to use original intake or go with aluminum after market. Any suggestions?? Running a Holley 650 carb.

Thanks,

Terry

Quil

I'm running a Holley 650 as well, a 4150 double pumper. The Performer RPM is a good performance manifold, and if you use a drop-base air cleaner, it will clear the stock hood. Performer RPM Air Gap is the big thing right now in terms of performance, but I think you could have clearance issues with it unless you use a drop-base cleaner and maybe a 2 inch filter. I'd go with the RPM in a pinch for about $200. Looks great, too.

arneoe

Changed your mind?

I wish you good luck Sir.... my Procomps turned out to be much better than one could expect . .. Happy seeking ....


Arne

RunningMan373

Who are you, my mother? WTF?

A., yea, i did change my mind and
B., bet they will outperform your Procomps.