Engine mods on an 86 4x4 for towing a 3000lb. travel trailer???

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Reddog74usa

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I recently picked up an 86 4x4 long bed that is bone stock and original with 68K miles on it. Very solid rust free AZ. truck but it runs like a slug so I want to zip it up a little so I can pull a 3000 LB. travel trailer. It's a 350 with a 700R4 and 3:73 gears. Looks like it's got every pollution control known to man on it. Any suggestions as to carb, cam, removing pollution controls, swapping out the exhaust ETC. would be appreciated. I'm in Colorado and elevations do change drastically so I'll need a combo that will work with that. NOT lookin for a hot rod just a nice crisp running truck.
 

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Well, before you start tearing into it, I'd make sure everything's in working order. I'd make sure there's not a single vacuum leak, I'd make sure your timing's good, I'd make sure you're getting good fuel, and I'd do an ignition tuneup (cap, rotor, plugs). I'd get a vacuum gauge to see what it's doing at idle if you can't see anything visibly broken. I think at least 18 inches of Hg should be your goal. As far as timing goes, I'd shoot for 8* initial. A little more if you can but don't let it ping. I can tell you that a few degrees of base timing make the difference between a slug and something feasible even on a stock motor. With fuel, I'd just change the filter for now. After that, I'd try her again and see what you think. It still may not be enough, but I'd be surprised if that didn't make a positive change. Looking ahead, I'd keep the Quadrajet, get a Comp 12-300-4 cam to put in it, see about some head work or aftermarket heads; get some long tube headers and do a nice dual exhaust, and maybe see about a new intake just to top it off. If you want to get rid of the EGR, then Edelbrock 2101 is good, or if you want to keep it, I'd go Edelbrock 3701. Those are non-Vortec intakes so if you're looking at Vortec heads, you'll need a higher end (and more expensive) intake. As far as emissions deletion, none of it really hurts you besides the air injection. That's gotta go anyways if you do headers. The EFE will also go when you remove the manifolds, and you can get rid of the thermal vacuum switch that goes with that. I would punch the cats, delete altogether, or get 49 state high flow ones. The EGR is up to you if you want another intake, or if you keep the factory one, you can get a block off plate and delete the solenoid that controls it. I'd keep the PCV valve and evap system if it were me. Those actually do a good service in my opinion. I'm probably missing a couple, but we covered EGR, EFE, PCV, Evap stuff, air injection, and the little solenoids and TVS's that control everything. The vacuum diagram will be an invaluable tool on what can go and what can't once you decide what your plan is. At the end, what matters most is that you don't have any vacuum leaks.
 

Reddog74usa

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Thanks for the info. I was just under the hood and saw a decal that indicated the truck was tuned for higher elevations. I know you don't get good performance in the higher altitudes but were only at 4800 feet. The truck goes down the road fine but at idle when cold it seems to have almost a dead miss but after it warms up it still idles rough but not near as bad as when it's cold. Also, once it's up to operating temp it runs nice and normal without a miss when you accelerate from say a red light. I'll go over ALL THE VACUME HOSES to see if any are cracked, soft or disconnected. I checked the cap and it looks good however the ignition wires look a bit on the old side so I guess I'll go thru the basics and see how that pans out. Come to think of it, it seems to be running like the timing is off. Like you said check it all out before tearing into it. It does only have 68K on it so the likelihood of it being some major should be pretty low.
 

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Agreed. Don't forget to check the carb base gasket by spraying starter fluid around it and seeing if it idles up. The EGR valve can be checked by pumping it up with a Mityvac and seeing if it holds or moving the diaphragm by hand to make sure it's not stuck and while it's up, cap your finger over the port on the valve, and see if it stays up. The rest of it can be pretty much done visually. Let us know what you find.
 

HotRodPC

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700r4 in a C20??? I sure feel sorry for that thing towing a 3000lb trailer, especially up and down elevations. For sure don't be towing in OD, especially with 3.73's.
 

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That is pushing the envelope there..
 

Reddog74usa

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Yep it is a 3/4 ton, it is a 4x4 and it does have a 700R4. Came that way from the factory. I'll post pics when I get that figured out
 

crazy4offroad

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Find a wrecked Z71 and go ahead and drop the coin for an LS and 4L60e and computer. Maybe go for 4.11 gears, rear overload springs and a rear anti sway bar and I would be confident pulling that camper anywhere. I saw somewhere swapping an LS into a vehicle with the heavy smog equipment of the 80s is the only legal way to de-smog them in some states.

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MikeB

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Any suggestions as to carb, cam, removing pollution controls, swapping out the exhaust ETC. would be appreciated. I'm in Colorado and elevations do change drastically so I'll need a combo that will work with that.
Well, a friend of mine who lives in Evergreen, CO still has to get his 1984 Land Cruiser periodically checked on a dyno for emissions compliance. So, unless that's not required in your part of the state, your engine will need to have all its emission controls installed and working properly.

Running like a slug may be due to many things, such as restricted exhaust (bad cat or heat riser), ignition timing not working properly, vacuum leak(s) etc. A common problem is an EGR valve that doesn't fully close and/or has a leaky gasket. Or you may have some cracked vacuum hoses, which is another common problem.
 

Keith Seymore

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Running like a slug may be due to many things, such as restricted exhaust (bad cat or heat riser), ignition timing not working properly, vacuum leak(s) etc. A common problem is an EGR valve that doesn't fully close and/or has a leaky gasket. Or you may have some cracked vacuum hoses, which is another common problem.

Agree. Sounds like there is a problem.

I towed my open car trailer (3900 lbs of car plus 1000 lbs of trailer) all over the US with no issues. 4.3L V6, MY6 Overdrive manual trans & 3.73 gears.

A 3000 lb travel trailer is not very heavy.

K
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HotRodPC

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Agree. Sounds like there is a problem.

I towed my open car trailer (3900 lbs of car plus 1000 lbs of trailer) all over the US with no issues. 4.3L V6, MY6 Overdrive manual trans & 3.73 gears.

A 3000 lb travel trailer is not very heavy.

K
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No, 3000lb trailer isn't hard. BUT, travel trailer tells me mega major wind drag. And we're talking about a an auto trans and a 700r4 at that, not a manual transmission. 2 huge factors in difference.
 

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Well, a friend of mine who lives in Evergreen, CO still has to get his 1984 Land Cruiser periodically checked on a dyno for emissions compliance. So, unless that's not required in your part of the state, your engine will need to have all its emission controls installed and working properly.

Running like a slug may be due to many things, such as restricted exhaust (bad cat or heat riser), ignition timing not working properly, vacuum leak(s) etc. A common problem is an EGR valve that doesn't fully close and/or has a leaky gasket. Or you may have some cracked vacuum hoses, which is another common problem.
And don't even worry about the emissions being a problem. Emissions ******** takes away alot less hp than people make it out to be. It's all hype so more will hate it. The deal with emissions and hate, has to do more with the **** being in your way, a **** ton of vacuum lines going everywhere and the fact that emissions can be a PITA if you want to add some mods like headers for example, or change to an Eddy intake. That's why people hate emissions. They do serve a worthy purpose even though we don't like them and don't want to admit it. At any rate, if there might be any chance whatsoever that you'll need to emissions test someday, leave the **** on there and make sure it's working properly. You have other fish to fry rather than taking off the emissions which will offer no noticeable gain whatsoever.
 

Reddog74usa

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Great info and I really appreciate it. I took a look at the truck today and found a vacume line off the heat riser so I repaired that but it's very stiff so I just set it in the open position. All the other vacuum lines looked good. I also checked egr valve operation with a vacuum pump and it works as it should. I never had an 86 and had to look hard to find the timing marks and would like to slap the engineer that came up with that location. Man I can't even see it so I'm going to set it by ear. I'll get the wife to power brake it and turn the dist. till it pings then slowly turn it till it doesn't. I WILL BE STANDING ON THE SIDE HA HA. Looks like the truck with the trans it has is really not well suited for what I want to do with it so I think I'll just put it up for sale and concentrate on my 79 C-10 runaround truck. It's a long bed with a 350 eng and turbo 350.
 

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No, 3000lb trailer isn't hard. BUT, travel trailer tells me mega major wind drag. And we're talking about a an auto trans and a 700r4 at that, not a manual transmission. 2 huge factors in difference.


I think our 5th wheel travel trailer was 3600 lbs and we pulled it with a series of 1/2 ton/swb/350 cu in/700R4 pickups with no issues. Our default rear axle ratio is 3.42 (non overdrive) or 3.73 (with an overdrive trans).

I would think the auto trans would be advantageous over a stick; the torque converter provides some multiplication during launch that you don't get with a flywheel. On occasion I would have preferred a little more first gear with the MY6 to get things rolling, especially starting out on a grade.

The set up below is not recommended and what prompted me to buy a 2500HD (trailer plus car = 7500 lb). The Haulmark proved to be a bit much for lil Red.

K
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700r4 in good shape and with a good cooler should be ok with a 3k trailer. Monitor the trans temp and don't beat on it.
 

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