[chevythmpr]

A friend and I are trying to deside how to build his 355. Its going in a 79 chevy 1/2 ton 4x4 auto, gears will be planned according to engine build. He is looking for as much power as he can get with it staying street friendly as it will be a fairly daily driver. He hasn't bought anything yet, so would like to see what you guys recomend from top to bottom. I know he's wanting a cam, possibly roller with noticable lope to it, and looking toward a gear drive. He's wanting to get different heads too, is vortec the way to go, or should he get aftermarket? No real budget on this motor, mainly wants it to be reliable and streetable. Thanks in advance.

[my87Z]

has he heard a motor with a gear drive, personally i can't stand them, all that noise would drive me nutts, and i do like my car loud but not like that.

vortecs would be a way to go, but if you guys dont have the experiance in doing your own port and polish work then i would look into a RHS's vortec style pro-torker heads, the cost will be about the same after you modify the stock ones at a machine shop.

what kind of transmisson, and does he want to change his stall, what kind of octane is he looking to run, pump gas i'm sure but does he want it to be able to run on 87 or is he okay with it running on 93, is there oversized tires on this truck.

[techinspector1]

Heavy truck. Needs cubic inches. Build it 383.

[my87Z]

i would agree with the 383 as well, you'll love the added torque

[chevythmpr]

It currently has a 350 turbo and he is willing to change stall as I told him he will probably have to, and 383 was talked about. What kind of machine work would need to be done to the block? I know it needs bored, anything else? And I believe he is wanting the quiet version of the gear drive. He can run 93 octane and the truck has 33s on it now I believe he is planning on going to a 35 eventually

[ap72]

a good double roller chain is better than those crappy 4 gear geardrive setups with the twin idlers. They get sloppy fast.

[techinspector1]

Originally Posted by chevythmpr

mainly wants it to be reliable and streetable.

OK, here's what I would do....This will take a while, so I'll be editing it for several hours....

Bore the block + 0.030" and cut the decks for 9.008" block deck height.
Locate a used set of L31 heads, casting number 12558062 or 10239906. I've had pretty good luck finding them on craigslist. Just go to auto parts and type in Vortec. Before you pay for them, disassemble them, clean them up and have them magnafluxed. If they check crack-free, then pay the loot and take 'em home. Hopefully you won't have to pay more than a hunnert bucks (sic) for the pair. Get the center-bolt valve covers with the heads if you can. It'll save lookin' for covers later. Some of the work that needs to be done to the heads to make them useable can be done at home with simple tools. If you don't have a 1/2" slow turning drill motor or a drill press, make plans to get one or the other. Set the valves aside, we will re-use them after a good valve job. Put the retainers, keepers and springs in a bag and store 'em to use on something else later. Get this tool from Summit and pull all the rocker arm studs out of the heads. The other side of the tool can be used as a guide for the 7/16-14 tap you will use to tap the heads for screw-in-studs. (see tap and die set below).
http://www.summitracing.com/parts/CCA-5306/

Use this cutter to cut spring seat pockets for 1.430" diameter springs and reduce the guide diameter to 0.630" for spring I.D. clearance....
http://www.summitracing.com/parts/CCA-4718/?rtype=10

This is the arbor to use with the cutter...
http://www.summitracing.com/parts/CCA-4732/

Scorpion roller rockers...
http://www.spiderautomotive.com/scorpion1000.html

2-piece timing cover, mounts cam bumper required for roller cam installation...makes advance/retard adjustments a snap..
http://www.summitracing.com/parts/CLO-9-221/

Valve springs to use with the cam we're gonna use....
http://www.summitracing.com/parts/CCA-986-16/

Retainers to use with the above springs....
http://www.summitracing.com/parts/CCA-740-16/

Locks to use with the above retainers....
http://www.summitracing.com/parts/CCA-611-16/

Shims to use with the above springs...
http://www.summitracing.com/parts/CCA-4754/

Screw-in rocker studs....
http://www.summitracing.com/parts/ARP-134-7101/
These are a little longer if you need the length...
http://www.summitracing.com/parts/ARP-134-7104/

Tap and die set....
http://www.summitracing.com/parts/WMR-W4001DB/?rtype=10

Guide cutter to cut very top of guides for 0.530" seals. Use with above listed arbor....
http://www.summitracing.com/parts/CCA-4726/

Valve guide seals....CompCams says this part number is Viton. Summit says this part number is Teflon
http://www.summitracing.com/parts/CCA-529-16/

Pushrod guide plates...
http://www.jegs.com/i/JEGS/555/20200...ductId=1206372
The cylinder head material will have to be milled down the thickness of these plates after removal of the pressed-in rocker arm studs.

We'll use these pistons....with the 64cc Vortec chambers, the static compression ratio will be 9.7:1
http://www.kb-silvolite.com/test/kb_...etails&P_id=93

Here's the crank....I used external balance because of lower cost and because it is minimum money to final balance at the shop...use a stock 400 damper/balancer and stock 400 flexplate or aftermarket flywheel if manual trans is being considered...
http://www.summitracing.com/parts/SCA-910375/

We'll use these rods. I like a 5.7" rod in a 383. Longer rods get the wrist pin up into the oil ring and I don't like it. These are clearanced for the cam lobes, so no grinding on the rods. Light grinding may be necessary at the bottom of the block at the pan rail to clear the big end of the rod.
http://www.summitracing.com/parts/SCA-25700P/

Retro-fit hydraulic roller cam and lifters....
http://www.summitracing.com/parts/CCA-CL12-432-8/
Doug Herbert sells the 12-432-8 cam only for $280....
http://www.dougherbert.com/xtremeene...h=83_84_88_660
And Chet Herbert hydraulic roller lifters for $280, so you might save a little money doin' it that way....
http://www.dougherbert.com/chetherbe...Path=83_93_684

[chevythmpr]

Any idea what kind of power we're looking at, and an estimate on the price tag?

[techinspector1]

Originally Posted by chevythmpr

Any idea what kind of power we're looking at, and an estimate on the price tag?

RPM HP TQ
2000 145 380
2500 183 384
3000 234 410
3500 296 445
4000 353 463
4500 397 463
5000 429 451
5500 437 417
6000 407 356

What I was tryin' to do here is to get all the tools together in one place so that when someone down the road says "how do you modify L31 heads for more lift and standard rockers instead of rail rockers", we would have all the part numbers and costs in one place. The other think I was thinkin' is that once a fellow does a set of these heads and has all the tooling and expertise, there's nothing to keep him from buying up all the L31's in his area, modifyin' them and selling them for a profit....
Furthermore, if he learned what to do and what not to do in the bowls and ports, he could wring a little more hp out of the heads and who knows.....he might become real popular....

[Blazin72]

Originally Posted by techinspector1

Heavy truck. Needs cubic inches. Build it 383.

Or my personal favorite: Supercharge it.
That was the route I took and I loved it. I want another one.

[bentwings]

I agree. A blower like yours would be a perfect match for the truck. I'd add some good pistons and JetHot coated headers.

[Blazin72]

That 142 rocked. It was perfect.

[chevythmpr]

I found a set of vortec heads on craigslist and was wondering if these would be worth the money or if I should start with stock heads
http://stlouis.craigslist.org/pts/1613547508.html

[my87Z]

Originally Posted by chevythmpr

I found a set of vortec heads on craigslist and was wondering if these would be worth the money or if I should start with stock heads
http://stlouis.craigslist.org/pts/1613547508.html

they are a set of vortecs, i can see the heart shape chamber and the bolt pattern. i dont like the fact that the combustion chambers aren't cleaned up and i would question what he spent the 500.00 on, as set of springs wont cost anywhere near that, i would ask what all machine work has been done to them.

it everyting checks out that is a pretty good price for a set of vortec heads

[techinspector1]

Main thing to do is completely disassemble them clean them and have them magnafluxed for cracks. It they're cracked, they're worth ZIP. See if you can make an arrangement with the dude that if they're not cracked, you pay the magnaflux. If they are cracked, he pays. Otherwise, at that price you can't afford NOT to buy 'em.