84 K10 is still gutless after cam heads intake

[INSIDIOUS '86]

Originally Posted by mrhino

Im with Centipede on those TBI heads. I been planning the engine build for my crew cab and actually went looking for those heads. iv done quite a bit of research on them. heres what iv found. There junk they dont flow for **** and that big hunk of cast right in the middle of the runner just flat ****s up the flow. at the upper rpm range, most guys throw them away. now that iv said that. these heads work great for low end torque. the swirl port actually works at low rpm about 3500 and under . and if you clean up the exhuast port it flow pretty good to. The set i have have been surfaced and mild pocket port done there are a small 58cc. and yes i will be running a dished piston. Im hoping for some awesome torque numbers and great fuel mileage. I guess we'll see how it goes.

Dont give up on that head just yet. I cant wait to get started on my engine. So keep us up to date on what you find.

Oh its just my opinion but I wouldn't run a edelbrock on anything. plus it might be to big. Im willing to bet if you got a smaller carb it would run better and accelerate better to. good luck to you

How would a smaller carb go faster? That makes no sense even 305s make more power with a 750 vs a 650. A cylinder head that is designed to help torque for a STREET car that's driven daily with a small cam and and small carb or injection would benefit. Otherwise in an out of stock application or anything that isn't trying to max you mpg on the street the heads are pretty much worthless.

So vortechs and zz4 l98 heads are about the best in terms of factory performance and price. The l98 head would be the best with the 58cc chamber and 175cc runners
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[CentipedePerformance]

Originally Posted by Firebirdjones

3.08's and 33's aren't a horrible combination, definately not the end of the world. You won't be setting stop lights on fire, but still very driveable.

I had an 84 blazer with 3.08's and the 700R4, and actually had a bone stock goodwrench 350 in it. Drove that for years, wasn't all that bad with the 3.06 first gear. Was just a driver though and was never interested in changing much else on it.

My current 72 blazer had factory 3.07 gears, I threw 33's on it. 350 turbo only had a 2.52 first gear, and the 355 was mild, forged flat tops, small RV type cam, performer rpm intake and 750 holley. It actually would get up and go decent considering. I modified the trans governor to hold the part throttle shifts longer for around town driving which helped alot with stop and go. Still knocked down 13 mpg city and 16 mpg highway.

Switched to a 6.0 LS engine and 4L60E, left everything else alone for a while. The 3.06 first gear and 1.62 second pepped things up, and it would actually lay some rubber with the 33's.

After a year of that I swapped in a set of 3.73's so I could enjoy more of that 6.0 and I think the setup now as a whole is about perfect.

Gears are funny like that though, you could put 4.88's in a 6 banger and feel like it would rotate the earth I have a couple other cars here with 4.56 and 4.88 gears, heck of alot of fun.

Oh it's definitely drive-able in it's current form. Far from horrible. Just not what I am looking for.

[CentipedePerformance]

Originally Posted by INSIDIOUS '86

How would a smaller carb go faster? That makes no sense even 305s make more power with a 750 vs a 650. A cylinder head that is designed to help torque for a STREET car that's driven daily with a small cam and and small carb or injection would benefit. Otherwise in an out of stock application or anything that isn't trying to max you mpg on the street the heads are pretty much worthless.

So vortechs and zz4 l98 heads are about the best in terms of factory performance and price. The l98 head would be the best with the 58cc chamber and 175cc runners
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I am absolutely not going to tear the top end back off this motor. I work full time, and am a full time college student. It took me a week to get it back together, all the while riding my Honda XR400 to work and school. Not happening. If I am stuck with what I have, I will just deal with it. I am not looking for a race motor, just a solid truck motor. I agree, vortecs or L98s would have been a better choice.....for more money. If money were no object, I would have just swapped in a 6.0/4l80e and associated electronics and left it stock, but I built it with what I could get, for a price I was willing to pay, with a realistic power goal in mind. I just don't think it feels like it should.

[bowtiemanchevyman]

what are your cam specs. you need to match all your parts to get your truck to run right. if your cam is to small or to big for your gears, nothing else will fix it. you cam throw all the money you want at it. but you need to match ever part in the motor and the drive train to what you want it to do other wise it will run like ****.

[mopar346]

Originally Posted by INSIDIOUS '86

How would a smaller carb go faster? That makes no sense even 305s make more power with a 750 vs a 650. A cylinder head that is designed to help torque for a STREET car that's driven daily with a small cam and and small carb or injection would benefit. Otherwise in an out of stock application or anything that isn't trying to max you mpg on the street the heads are pretty much worthless.

So vortechs and zz4 l98 heads are about the best in terms of factory performance and price. The l98 head would be the best with the 58cc chamber and 175cc runners
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Bigger better badder, mmmmmmmmmm.

If the carb is too big or not adjusted/jetted properly it can dump too much fuel and cause boggs and hesitation. Dumping too much air with out fuel or visa versa or too much of both can definitely have an ill effect on performance.

One thing I haven't seen discussed is fuel pump and pressure. Which I don't think is gonna be an issue unless there is something wrong with yours.

Maybe I missed it, what carb and pump set up are you running?

[mrhino]

Originally Posted by INSIDIOUS '86

How would a smaller carb go faster? That makes no sense even 305s make more power with a 750 vs a 650.

Hell, might as well put on a 850 or 1000 cfm demon!

Originally Posted by INSIDIOUS '86

A cylinder head that is designed to help torque for a STREET car that's driven daily with a small cam and and small carb or injection would benefit. Otherwise in an out of stock application or anything that isn't trying to max you mpg on the street the heads are pretty much worthless.

I completely agree with you on this point. except to say those heads were actually designed for the TBI trucks. They were looking for more torque and mpg for the trucks thats why they were designed this way.

Originally Posted by INSIDIOUS '86

So vortechs and zz4 l98 heads are about the best in terms of factory performance and price. The l98 head would be the best with the 58cc chamber and 175cc runners
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Once again I agree with you. but the man did not build a high performance engine looking for hp. He said he researched those heads, if he truly did, then he would have found that they were best for low rpm torque, exactly what you would need for a daily driven truck with big tires and 3.08's. There is a reason the put L98 heads on corvettes and Low rpm swirl ports on trucks!

[BigBlocksRule]

Swap some 28" or 29" wheels/tires onto it for a test. It's not all in the diameter's play into gearing, big honkin' tires and wheels are a lot harder to turn because of their weight, too!

[mopar346]

Originally Posted by BigBlocksRule

Swap some 28" or 29" wheels/tires onto it for a test. It's not all in the diameter's play into gearing, big honkin' tires and wheels are a lot harder to turn because of their weight, too!

Great point.

[CentipedePerformance]

Melling MTC-1
Thats the cam

I am running a 600 cfm Edlebrock, and a Carter 72 GPH rotary vane pump.

[CentipedePerformance]

I think the main issue was hit on early in the thread. 3.08 gears with a 33" tire is probably going to take the steam out of almost any mild motor. Stock is *I believe* a 275/35/15, a 33" tall tire is roughly 14% larger. With the increase in tire size, that's like putting 2.65 rear gears in the truck. Not to mention the extra rotating mass of the taller, wider, and knobbier tires. First gear on the 700r4 is 3.06:1 which is pretty low for an automatic, which is why first gear still feels ok, but it will do darn near 50 mph in first gear. I have found gear sets for pretty cheap, so I am considering throwing some in, but we will see. The truck is OK for now, just a bit disappointing.

[Firebirdjones]

Originally Posted by BigBlocksRule

Swap some 28" or 29" wheels/tires onto it for a test. It's not all in the diameter's play into gearing, big honkin' tires and wheels are a lot harder to turn because of their weight, too!

This is why I put a little thought into the tire and wheel combos I run.

I run 33's, but they are 10.5's,,,since the 12.5's are heavier and harder to turn, and have more rolling resistance due to their width. I put these on a 15" aluminum wheel for lighter weight. Steel rims are just too heavy.

You can also look at tire brands, as each brand will weigh more or less than the next brand. Some tires, even though the same dimensions, can weigh as much as 5-8 lbs. more per tire than other brands. That adds up. Then you figure in the weight of a particular wheel and you begin really add some weight, multiply by 4 and you could be talking about 50 lbs. total or more. That's not just rotational mass, but overall weight of the truck too,,,it's a double whammy.

I also pay attention to tread pattern,,,as the more aggressive tread will have more rolling resistance. I prefer to keep it mild for a daily driven truck so I use the BFG all terrains, it's about as mild of a truck tire as you can get while still 4x4 capable in mild conditions, runs quiet, less rolling resistance.

All of these things will affect rolling resistance, how well the truck brakes, the amount of HP to turn it,,,and in the end,,,your gas mileage.

[INSIDIOUS '86]

Originally Posted by CentipedePerformance

I am absolutely not going to tear the top end back off this motor. I work full time, and am a full time college student. It took me a week to get it back together, all the while riding my Honda XR400 to work and school. Not happening. If I am stuck with what I have, I will just deal with it. I am not looking for a race motor, just a solid truck motor. I agree, vortecs or L98s would have been a better choice.....for more money. If money were no object, I would have just swapped in a 6.0/4l80e and associated electronics and left it stock, but I built it with what I could get, for a price I was willing to pay, with a realistic power goal in mind. I just don't think it feels like it should.

I know all to well what that's like. Except my bike has pedals haha. I'm putting together another engine myself and am using some vortechs for about 400$ the factory l98s are cheap as well but about 500-700 assembled. I'm keeping the low compression rotating assembly and adding a lunati 268 cam. Should be around 350hp and 400ft torque and run on crap gas to boot. My rig with a 700r4 and 305 would still spank some a$$ with 2:73 gears but I could also drop to second at 55mph lol
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