Plans for a 350 - Give me some feedback

[cracker0169]

I've got an 1981 K10, 3.73 gears with 37" mt/r's. It has a SM 465 trans with 205 transfer case.

I just pulled the motor from my donor and havent dropped the pan to check main bolts. The block is a 3970010 with 462624 heads (76cc). I havent yanked the heads yet to check bore or to see the valve sizes (moretec.com says either 1.94s or 2.02s).  I am going to keep it stock stroke (3.48). I'm planning on ordering a set of Speed Pro Pistons with rings (approx 9.4 with 76cc heads) when I determine bore. I've already got a set of Comp Cam beehives that will work with the cam.I already have a Comp Cam Xtreme 4x4 cam set CL12-239-3:
Operating Range: 1300-5600 RPM
Duration Advertised: 262° Intake / 270° Exhaust
Duration @ .050'' Lift: 218° Intake / 226° Exhaust
Valve Lift w/1.5 Rockers: .462'' Intake / .480'' Exhaust
Lobe Separation Angle: 111°

Gonna bolt on a gear drive instead of a chain set. Up top, I've got an RPM intake to bolt on with a 750 Edelbrock.  My plans for ignition include Proform high output HEI set up with MDS 8.5 super conductor wires.

What do you guys think? Im shooting for streetability plus gobs of power off road. My desktop dyno program (and you know the accuracy of them) predicts 415lb ft @4000 and 369hp @ 5000 with some port matching on the heads and intake. Give me some feedback!

Forgot to mention exhaust.  1 5/8 primary, 3in collector long tube headers with 2.5" straight pipes (no mufflers) with 4x18" tips.

[VileZambonie]

You aren't going to have gobs of power but it will definitely be there when you need it. I would skip out on the gear drive (you don't need it) and maybe go a little bigger on the cam and get roller rockers along with screw in studs and guide plates. Porting and port matching is a good idea too.

[cracker0169]

Screw in studs are part of the plan as are the guide plates. I am gonna get some cash saved back up then order a set of roller rockers. I played with the cam numbers on the dyno program and the larger cam pushed my power band higher in the rpm's than I liked. Torque and HP were better with this cam until you got up around 6000. I'm setting my redline at 6000 max! Thanks for the input.

Anyone else?

[Blue 82]

ditch those heads and the related parts and $$$ for machine work
sell em on craigslist
forget the dome pistons
forget the gear drive

Take the money and buy a set of new heads
The RHS Vortecs are a great deal (you can use any intake manifold)
By the time you rebuild those stockers with new valves, guides, studs, springs,  real valve job (serdi), get em tanked and surfaced etc...., could have bought new heads that will actually make some power, not choke your engine. You could spend some more $$$ getting the old stockers ported, but you would still the antiquated combustion chamber design...

http://www.racingheadservice.com/Information/Technical/Heads/ChevyVortec-Heads.asp

here's the best place to get em
http://www.competitionproducts.com/products.asp?dept=693

Speed Pro Hypereutectics flat-tops are all you need for a truck piston with the RHS head. H-345 np is the uncoated version that can be found for $125 or less a set ( with the pins included. The version with the coated skirts are a few bucks more.

For a few bucks extra, durabond makes coated cam bearings, a wise investment

Use a decent oil pan, Milodon makes a good pan with a windage tray for under $150. If you are gonna buzz the RPM's you are going to need some sort of oil control.

Use ARP rods bolts, Find a (new) ZZ4 balancer, and get the thing balanced

You should be able to easily make 350+hp and it will last 100,000+ miles

that's my 2 cents worth....

[SUX2BU99]

^ Those RHS Vortecs are a great deal and they already have the LT1 springs to accept the higher lift that your cam has (stock Vortec springs don't). An alternate that is the same price are the Dart Iron Eagle S/S heads that those same people also sell for I think the same price (I bought the Darts and just had them put on).

[cracker0169]

Heads are off...

Engine was punched out .030 when it was rebuilt in late 90s. As long as the bore checks out, it should save me some money at the machine shop. It has a set of flat tops with 4 valve reliefs so I'm going to keep those as long as they arent cast. For the heads, they are 1.94/1.50 heads.  I'm going to get this thing freshened up and after I put some money back I'm going to find a good set of 64cc heads (give me roughly 10:1 or so with flat tops) but until then, Im gonna stick with the 76ers. I should do appreciate the feedback guys.

[nativetexan]

speaking of machine work $$$.

I talked to my mechanic about machine work also. He gave me a price of about 450-500 for the engine block [with the bottom end still in] and the heads. Is that a pretty good price? I figure it is since it includes the engine and the heads. Also, I do want my truck to sound like it has a new cam in it. Vile, do you think that cam you suggested will sound pretty good in that engine?? 

[Blue 82]

Heads are off...

Engine was punched out .030 when it was rebuilt in late 90s. As long as the bore checks out, it should save me some money at the machine shop. It has a set of flat tops with 4 valve reliefs so I'm going to keep those as long as they arent cast. For the heads, they are 1.94/1.50 heads.  I'm going to get this thing freshened up and after I put some money back I'm going to find a good set of 64cc heads (give me roughly 10:1 or so with flat tops) but until then, Im gonna stick with the 76ers. I should do appreciate the feedback guys.

GM used a .022" steel shim head gasket with those heads
Using a gasket like a Fel Pro .039 will drop your compression

if the bore checks out and the piston skirts are OK,
a touch (light) hone would be required
not a dingle ball hone, but one done on an automated machine (sunnen), to match the finish dictated by your rings.

A little bowl work on those heads will go a long way toward stretching your dollar
While this is not a SBC head, it shows the the before/after

[Blue 82]

here's a better pic (non sbc head for demo purposes)


Check those heads
look into the center exhaust ports and see if both (ports) have the exhaust crossover holes
in the earlier heads only "one" of the center exhaust ports was cast with the ex crossover
after 1975 some had "both" center ports cast with the ex crossover, these form a "Y" passage to the intake side of the head. These are known as lightweight castings

If you have the lightweight castings (made after 1975), these are very prone to cracking

my $.02

[lowbucktruck]

speaking of machine work $$$.

I talked to my mechanic about machine work also. He gave me a price of about 450-500 for the engine block [with the bottom end still in] and the heads. Is that a pretty good price? I figure it is since it includes the engine and the heads. Also, I do want my truck to sound like it has a new cam in it. Vile, do you think that cam you suggested will sound pretty good in that engine?? 

That is a decent quote on the machine work.  I recently got a quote from my machine shop for my old 350 block and it was right at $500.

[comp]

if you are out looking for blocks get a "roller cam " one