I copied this from another thread...




Martin...if your really into this tow cam deal...


I've got the perfect project...1986 C-30 4-door dually 6.0L/4l80e...


It's kinda' dirty, but it gets used hard, all year long, and it could use more TQ!


I built this back in about 2008 if I remember right. Head and shoulders above the old 7.4L/SM465 combo...but I'm ready to step it up...


Any and all advice from anyone is greatly appreciated...


(EDIT: If this needs to be in the "Conversions/Hybrids" section, that's ok...I just thought there might be more dr whigham, KCS type guys over here.)

 

Little more info on the combo...

Donor rig, 2000 2500 Silverado.

Stock truck intake.
F-body Ex manifolds.
2.75" dual exhaust, C70 truck stainless muflers.
Stock converter.
Cast iron 873 cyl heads.
3.55 rear gear.
Canned tune from Wait4me.

 

I am certain Martin, Kip, or BT can help BUT I would still put more gear in it.

Happen to know what it weighs? Betting less than a current half ton crew shortbox 4x4.
I had a 1989 with the 454 and it was pretty weak, the swap was a great improvement I am sure.

 

Thanks for starting this thread!! We all can't afford 70k new diesel trucks. What would be awesome if we can get a real full weight F-body load it up on a open trailer and give real world results/opinions on each cam.

 

So are you looking for off-idle(super-low RPM) torque or are you willing to make the thing rev a little and do some "work" to get that torque? What are the gear ratios in your 4L80? Tire diameter? What weight(s) do you usually haul? What does your current rig weigh with you in it and full tank(s)?

I am by far not an expert but it seems that the above info will get you headed in the right direction. My first thought is updating your intake to a factory gen-IV model unless you are trying to keep your RPMs in diesel territory. Have you had it tuned? Also are you stuck on factory converter or is that just the way it all went in? With such a big vehicle a slight stall might get you rolling faster and let you turn a few more RPM without hurting cruise RPM/mileage too badly.

 

Gear ratios are for a 4L80E.....

1st-2.48
2nd-1.48
3rd-1.00
4th-0.75

Most guys I know that tows want more power instantly... that means off-idle. Hope Cattle chime in soon.

 

I have the crane cam part # (1449041) specs 210/218 - 114 - .551 lift and it does exactly what your looking for, more power from of idle to 6000 rpm. Holds overdrive on hills where it would downshift before.

 

I have heard nothing but great things about that cam!! It's been tested in a couple of magazines car craft, hot rod etc.. .

 

I think this is the perfect section for it myself. Its internal engine, dealing with camshaft selection.

I'm very interested as well. I think there's definitely a market for these types of cams. I have an L92 6.2 though...

 

The LY6 and L92 is close to the same engine I believe. L92 having 12 more cubes over the LY6. Both running the rectangular port head. Not sure what's the compression differences between the two. I've read this link I'm about to share over and over. It's very interesting. I'm willing to bet the 210 cam is very quiet like with no lope!! With that cam the 6.0 with L92 heads exceeded 460 horses and 460 ft lbs of torque.

http://www.hotrod.com/how-to/engine/hrdp-0711-6l-hop-up-pt-2/

 

You want to best cam for your a Tow Truck? Guess what? It will not have the most Power or Torque compaired to what most people wil recomend�� it will not win a dyno test�� The best cam will have good vacuum at idle. Will not lope unless you tune it to sound like that. It will pull hard from idle to 3800 with a maximum of half throttle. That is where you drive 99% of the time not to the floor or max RPMS. No one would like the specs and they sure would not like the HP numbers. Most magazine dyno test are done wrong not real world conditions. Most show graphs of the run starting at 3500�� You don't tow with a dyno or a flow branch. So be careful when choosing a cam for towing or any other combination. The guy with the most HP hardly ever wins��

 

Yes, idle is almost like stock no surging or stalling with stock idle settings

 

I run a 31" tire.

Pickup weighs 6320#'s

Usually weigh between 8000-14000lbs when loaded.

 

Thanks for the response Kip...

And your right...most of my time (probably 99%) is spent between 1700-2300 RPM with a max of under 4000.

I'll give you a call tomorrow.

 

Sounds like the experts have you covered cam-wise. I'm running one of Kip's cams and have no complaints.

Have you thought about finding a cheap set of factory heads with a bit smaller combustion chamber? Seems like adding compression is an easy way to add power everywhere, including low RPM. Caveat is that you might not be able to run regular unleaded depending on tune and other factors. Aluminum heads are in theory less detonation-prone though and 241s, 853s can be found for $150 a set in good shape it seems.

Good luck with the build. Sweet truck. Going to do an old-school Chevy truck one of these days myself I hope.

 

Like Kip said, if you’re looking for a camshaft with great torque down low in the rpm range a lot of the popular cam shafts are going to be too big. For reference, when I talked to a couple of the sponsors about a custom camshaft for my K5 Blazer swap they were all in the 206/212, 110 lsa and 208/212, 113+2 lsa range. Those 3.55 gears aren’t helping you in the towing department either and I’d probably look at a set of 4.10’s or maybe lower if it’s a dedicated hauling rig.

Depending on what your budget is, you may want to look at swapping to the newer style intake, 243 heads, and maybe even a set of long tubes to go along with the camshaft. Ideally you would want to do it all at once to make sure that all of your components are designed to work well together instead of being limited in the future or having to pay for multiple re-tunes on the PCM… A lightly used set of 243 heads can be had fairly cheap and will flow a little better than the 317’s on it now and will also get you a nice compression bump with their smaller combustion chamber. The TBSS/NNBS can also be had fairly cheap and is better flowing than the one you have on there now and also use a larger throttle body (87mm stock or 92mm aftermarket). Long tubes are great for torque and there are now a few companies like Hooker and Schoenfield making them for square body LS swaps now.

I really like how your truck is turning out. I love these old square body trucks and am gathering the last of the parts for my 5.3/4l80e swap in my K5. Good luck with your project I’ll definitely be watching to see how everything turns out.

 

Great post. I have heard the tbss intake is worth 20hp/20ft lbs over the truck intake.

 

Keep in mind thats on engine dyno . not the rwhp . It will not do anything close to that in a big heavy truck.

 

My truck came from the factory with 4.10 and I hated them. Then put 35's on it and of course hated them even more. Never even bothered with 4th gear. I put 4.88's in and they helped, but wish I would have gone with 5.13's. LS motors are NOT small or big block chevy's. My point is that those 3.55's are killing you as others suggested. Spend $200 plus a rebuild kit and throw a 4.56 back there. Best bang for the buck you can buy and will make you much much happier.

 

Amen!

Kip hit the nail on the head. Guys call me or email all the time wanting camshafts for their trucks. The problem most of them have is they want super choppy cams with stock stall converters. Oh, and they want to still tow 6k+ lbs.!!!

As someone else mentioned too, and from what I've been reading in my research to purchase my own light duty tow pig, 1500's and 2500's in tow haul mode tend to turn some RPM's when loaded down with 6k+ lbs. In my research it was not uncommon to find some 1500's when loaded with 5-7k lbs. in hilly terrain needing well over 3500rpm to make it up a hill and to keep their speed. Same went for 2500's with 7-9k+ lbs. especially with the 2500HD's having 4.10 gears factory. They liked to turn some RPM.

With the right cam for the application these kind of RPM's aren't as necessary or at least the amount of time spent at these RPM's is much less as the engine has more low end grunt and more power from 1500-3000rpm and no loss in off idle torque.

As Kip said, power range for a vehicle that tows heavy loads should be 600-4000rpm. Look at the factory 6.0 torque curve. Makes peak torque at 4000rpm and peak HP at 4400rpm. The cam specs needed to optimize this power band will not impress your buddies and they will not make much if any noise at idle.

The magazine guys tout, "80hp gains!!!" Yea at 6000rpm+ where a tow pig will never spend any of its time. It's snake oil for those that don't know better.
One of my first things I'll be doing is long tube headers and a y-pipe on mine, along with a good cold air intake. Then it will be 799 heads milled .030", TBSS 90mm intake and a camshaft with PAC 1218 springs.

I feel your suggestion for added compression is an excellent one. Anytime you can squeeze more cylinder pressure out of an application that needs more torque is a benefit. As that added cylinder pressure has a direct effect on torque production.

I tend to agree with the gearing comments too. Although a 80e is stronger than a 60e and I'd rather have one to tow with, it lacks a low first gear ratio. This makes having lower rear gears a must IMO which is why GM gave the 2500HD 6.0 gas trucks a 4.10 rear gear from the factory. Add to the fact that this engine and drivetrain is in an even heavier truck than a 2500HD(SRW that is) and it really starts to need that lower rear gear.