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Snoozin' 350 into Building the Rockbeast

I've got a goodwrench350 block. I've pulled the heads/intake on it and it's not machined for the spider down in the valley.

The heads are not worth putting any money into rebuilding, they're a thin casting that are prone to cracking.

I was looking at vortec heads when I replaced mine but ended up doing some old style because I'd already had an edelbrock intake and would have had to replace it for the bolt pattern. You also are supposed to run self centering rockers on those heads. And you'll need center bolt valve covers so more $$ It's all doable but it adds up. And if you need to keep egr for emissions that's another tough one. Edelbrock makes one w/ provisions for egr but you'd have to weld in a tube from your headers to get the gasses over.

I can upload a pic if you're interested in seeing what's in there.

Josh
 
I would just drop a $500 4.8L in there instead. 290hp / 300 ft lbs will kick a 5.7L square in the butt, run around it and kick it in the butt again before it even realized what happened. :haha:

There is a lot of money that is involved with swapping heads, intakes, camshafts etc around. Better to spend that money on motor mounts, fuel system etc instead :whistle:

:popcorn:
 
Russell said:
I would just drop a $500 4.8L in there instead. 290hp / 300 ft lbs will kick a 5.7L square in the butt, run around it and kick it in the butt again before it even realized what happened. :haha:

There is a lot of money that is involved with swapping heads, intakes, camshafts etc around. Better to spend that money on motor mounts, fuel system etc instead :whistle:

:popcorn:
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This is a good suggestion.^^^

I had a 99 with the 4.8l. I liked the engine o.k., I had issues with the truck itself. I would have kept it if it had the 5.3.

F.Y.I. the LS truck motors are easily good for 200k miles, that's something to consider. And they have good power and mileage in stock form.
 
OK guys we're getting deep man LOL
The guy I bought this motor from ordered it new thru a dealership. He wasn't real talkative and since I was holding him to his price of 300 bucks after his old lady spazzed on him over that price I got it yanked and rolled.
Not sure what the hell he ordered but it seems like a mish mash...carbed not TBI, 1 piece seal not 2, old style heads but block does have roller provisions, mechanical fuel pump, bolt holes for accessories are larger than my old 350....

If I went the Vortec route a friend says he has all I need to do the job-heads,cam,valve train,timing gear,intake and carb. That all hinges on how much he wants and when I can catch him to get it.
If don't get that deal I'm going with headers and a cam that will get the most out of those 1.94/1.5 76cc heads as is.

If I had to pull that bastid again I'd be dropping the 454/4L80 my other gearhead buddy has been taunting me with and be done with it. If I had the cash to have done that instead of the crate 350 I would have.

I've got 3.73s so that helps the torque.
I appreciate all the advice guys, I'm just looking to improve what I've got for now.
When I do finally start making some damn money I can save up for the beastly upgrades and drop the current combo in a pickup as a 2nd work truck.
 
Swapped my Holley out for one my friend gave me. Smaller pump nozzle,bigger jets. The snoozer isn't quite as sleepy now. I'm thinking the budget cam and Hedmans will go a long way after all. More of my allowance for body work!
 
if it has flat top pistons the 76cc chambers might not be too bad with the 268 cam or 1 size smaller... I run the 274s cam with 10.5:1 compression. its 236/242 @.050 and I wouldn't run it with any less compression than I have now. I have heard a sbc with the 268 cam and you can hear a little thump in it. I would think that 9:1 compression would be minimum
 
Depends on your deck height and piston pin location. Flat top yes, but depends on piston pin location for accurate comp ratio.

Stock config with 76 cc heads and stock Pistons your lucky to be at 8.1

Piston could be .020 or .040 etc in the hole affecting comp ratio as well as the head gasket thickness.

I run vortecs on my 355, 268h cam 218@50 454 lift. Th350 trans, 4.10's with 35's, right around 9.1 compression. (Just under) keep your compression around 9.1 and you shouldn't have a detonation problem. I run 87 pump gas.

I also Run a 2000 stall and am very pleased With the power. I do feel I need the 2000 stall

Depending on what tires and gear ratio you have will make a difference.

You might want to consider one step down from the 268 and won't have any issues with stock vortecs on the lift and will be good for a daily driver.

By the way I can barely hear a thump at idle especially at running temp.

Of course IMHO.
 
I posted earlier that it ran fine on 87 but I'd been running 93 for the most part lately, had the timing just about perfect and put 87 in the other day...sounded like a bushel of crabs going up hills to work...put 93 in again and not a rattle so I'm not sure what the compression is going by that. I assumed it was typical 8.1 at best. Wish I knew what this guy had done, his wife was snapping at him about "extras" that ran the price up but I didn't push my luck asking questions. I doubt the cam is anything special, it idles smooth as silk.
I'm running 3.73s now, it had 3.41s but I swapped in a rear out of a 76 and it was instant torque upgrade.
I was running the Holley I bought new 3 years back, 80457S, which did well for the 2 old 350s I had it on but seemed lean in the cruise circuit. I put an 1850 on yesterday with a 28 pump shot nozzle and 70 primaries. Looked up the specs on mine and it was a 2 point drop on nozzle and 5 point increase on jets....test drive impressed me! Seems someone set it up for a 350 already. I'll know more after this ride to work thru hill and dale hell:rolleyes: It certainly made a difference in take off and passing gear at 50mph.

Due to money constraints I'm leaning towards the flat tappet Comp with a little less lift than the 268 or a Summit comparable cam. Since the carb was such an improvement I believe the cam and some headers will let it breathe better and give me a motor I can be happy with for a while.
Rather than spending too much for "medium" improvements on this 350 I'll run it until I can afford a Big Block and this one will be a nice,well tested power plant for a lighter 2nd work truck in the future.
 
Back from the dead here. We were talking about stock Vortecs and someone said they were .470 on the lift....now I've been looking at cams to fit that lift but I didn't BUY Vortecs heads :doah:so I thought I should ask : What's the typical lift on bone stock chevy truck 350 crate replacements? Mine have 14079261 on them but I can't find the specs on that number. Anyone got a nice safe number to go by?
 
Another question: With a heavy Suburban and mostly stock ,carbed 350 what RPM range would be better? 1500-4000 or Idle-4500? Where would the power range crap out? Looking for good takeoff and decent highway response in a loaded down work beast. Thinking about either Summit 1101 or 1102 , maybe Comp XE256H or X4250H depending on my allowance when I order it.
 
I don't think I'd be considering a cam that exceeds about .450" lift in any case. Most truck cams that have good low end are not high lift cams. There are so many options around that lift that it's probably not worth worrying about cramming more lift into the cam. Realistically if there was any question you'd need to know at what lift the springs coil bound, seat pressure, and then run checking springs to see how much lift you could get away with before there are clearance issues.

See if you can get your hands on desktop dyno or similar and start running the numbers. My opinion is to run headers, make sure the fueling and timing is good, and see what you think. Headers are normally worth 25HP or so on a small block, that's significant for the cost.
 
Thanks Dyeager. I've been scrounging info on this motor from the start. Wasn't sure what max lift was for the heads but was trying to stay under .470 but now I can revise that lift range. My hopes are to put in a nice torquey cam for low/midrange, headers and lose the Holley 600 for a well tuned Quadrajet.

OK the Summit 1102 has .421/.444 lift with factory rockers. 1101 comes in less than that.
 
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I wouldn't spend time on a cam until I had headers, well-tuned carb, and knew my timing was good. Cam can make a big difference, but if everything else isn't up to snuff, you might be impressed without the hassle of selecting a cam.
 
Well hell I was going backwards as usual :dunno: I was going with headers and Qjet anyway so may as well go that route first and see what I've got.
 
evolve991 said:
Well hell I was going backwards as usual :dunno: I was going with headers and Qjet anyway so may as well go that route first and see what I've got.
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Exactly. Headers and carb will work with whatever you end up deciding in the end, going to spend that money anyway, spend it up front, see what the results are, then plan your strategy from there. I've got a real mild cam in mine, and although a completely different induction system and heads, I'm happy with the power. It does run out of steam fairly quickly, but if you are looking for low end, that's the tradeoff.
 
Check out the comp 12-231-2 cam, it's there smallest 4x4 cam.

I've got it in a 305 HO headed 350, gasket matched, headers, performer intake, 670 street avenger.

It's now powerhouse, but it's a solid torquey little motor. Itll turn my 38s no problem.
 
Thats the one I labeled as X4 250H Bowtie. Right in my range.
Dyeager I'm stumped between low and low/midrange tweak. I want the heavy beast to take off strong and have some juice left for on ramps and highway but not looking to scream on the top end
 
evolve991 said:
Thats the one I labeled as X4 250H Bowtie. Right in my range.
Dyeager I'm stumped between low and low/midrange tweak. I want the heavy beast to take off strong and have some juice left for on ramps and highway but not looking to scream on the top end
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Figure out your RPM's where your shift points are if auto, and if manual, how many MPH you can get going in gear before you have to shift. Someone else can chime in if they know better, but with a factory or low performance engine, 4-4500RPM is probably a good choice to figure you are potentially getting into engine longevity/valve float issues. Not saying they can't be turned faster, just that without knowing what RPM range the components in the engine are designed for, that's a good upper limit.

I've got my ECM set to "rev limit" at 4500RPM, which works out to 25MPH in 1st (really 2nd in the SM465) and somewhere around 55MPH in 2nd. Easily pull 70MPH by the time I hit the freeway if I want/need.
 
OK you guys will be all over me on this LOL but......Timing is set by ear , I don't have a timing light or any gearhead buddies to borrow one from. My Dad was old school Chevy and taught me long ago to listen to her purr. Been running with no speedo for a couple years but the shift points are right around yours Dyeager. I don't want to overcam for sure that's why I'm asking newbie questions :smirk:

HEADERS! Buddy of mine says he's got a pair that came off an 84 2WD. Doesn't know what brand or number but looking on Summit I see some familiar numbers for both 2 and 4WD so may have those covered real soon.
 
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