Fifth wheel in a '72 LWB C10...

[Chevelle454]

Well, first of all...it's been a long time since I've been here but I'm picking up my old projects again and it's good to be back!

So here's my dilemma...

I recently purchased a 24' 6500lb fifth wheel camper trailer. I was told that my 2002 F150 4x4 5.4L would pull it, but it would be pretty borderline.... Of course I didn't have a fifth wheel hitch in the truck already to test it out first, but the trailer was a good deal so I went through with it and purchased it. I bought and installed the hitch in the Ford, only to discover that it has a hell of a time just getting to 55 mph. I can hit 65 or 70, but you have to floor it the whole way there and then stay about 3/4 throttle to maintain speed on a flat grade. Wind seems to be the biggest factor, as the trailer sits about twice as high as the truck. Obviously, this is not going to work...

So my new idea...

I have two Chevy trucks, a 1972 C10 and a 1972 C20, both LWB.

The C20 had an engine fire, so there is no engine or transmission in it and the cab is pretty burned up inside. It is mostly rust free, the frame is in very nice shape. But the Eaton rear needs a rebuild, and it needs all new ball joints, tie rods, shocks, springs, etc...

The C10 is in nice shape. It has a mild built 350, 4 speed transmission and 4.10 rear end. This truck also needs new shocks and springs as they are sagging pretty good.

So if at all possible, I would like to use some combination of parts between the two trucks to build a truck that is capable of hauling my fifth wheel camper. Would the C10 be alright with possibly just some 3/4 ton springs in it? Too much stress for a 10 bolt 1/2 ton rear end? Will rear drum brakes be sufficient to stop this thing with a load like that behind it (with trailer brakes)?

Any suggestions on what to do here?

[dan76]

Interesting dilemma. One question I have is whether the frame on the c20 is dimensionally different (thus stronger) than the C10. Perhaps more knowledgeable members can provide this data.

If the C20 is indeed stronger, I'd transfer the good parts from the C10 over to the 20. I do know the brakes/suspension on the C20 are stouter than on the C10. However due to the wind resistance posed by the trailer, I'd also suggest looking for a BBC rather than keeping the 350. You'll need the torque at lower RPM to keep the beast moving against a headwind and on grades.

[PanelDeland]

That's not so much weight but it is a lot of trailer,as in take a 4xx8 sheet of plywood and turn it crosswise and carry it into a 16-20 mph wind.I'm thinking even a C20 is gonna be marginal for towing that much wall.But if that's what you got.

I would go with the C20 frame and suspension,Make sure the brakes are great shape,and not expect much more performance from the 350 than you have now with the Furd.You're gonna need a lot of torque to tow that with and that probably means a Big block or deisel.Cruise a few campgrounds and check out CL and the Bay to see what combo's are for sale.Usually they will be about a match and you can gain some idea of whether it will work for you or not.

[Chevelle454]

Originally Posted by dan76

Interesting dilemma. One question I have is whether the frame on the c20 is dimensionally different (thus stronger) than the C10. Perhaps more knowledgeable members can provide this data.

If the C20 is indeed stronger, I'd transfer the good parts from the C10 over to the 20. I do know the brakes/suspension on the C20 are stouter than on the C10. However due to the wind resistance posed by the trailer, I'd also suggest looking for a BBC rather than keeping the 350. You'll need the torque at lower RPM to keep the beast moving against a headwind and on grades.

The C10 with the current gearing is pushing around 3000 RPM at 65mph. The 350 makes good power, I would guess around 350 HP, not sure about torque.

The Ford is actually geared at 3.55 and also has oversized tires so I would guess this is where I am losing a lot of power... But re-gearing both front and rear axles is not a cost effective option at this point.

[dccarpenter]

I'm wondering if the issue is more gearing than engine, I'd be curious as to the rear gears on that f150? Also, is the 4 speed on the c10 a sm465? If so it won't like speeds over 55 loaded or unloaded but will get it moving much easier, slap a Ranger overdrive or gear vendors on it and you have a superb towing transmission. If it's the saginaw with overdrive than your already set and the thing should do nicely, again you could add a Ranger overdrive or gear vendors for even more gear options.

The c10 and c20 frames are the same in terms of height and stoutness, I'd swap in the rear axle and leafs from the c20 to the c10. The rear drums on the c20 will be fine. Honestly swapping just the suspension components would probably do ya. Put some nice shocks in the front, replace any body mounts/rubber that looks iffy. I think that c10 can pull that trailer nicely for you with the right setup, also confer with a local towing expert (maybe seek out a board member) to make sure your weight distribution is setup right with the 5th wheel, it can make a big difference with that kind of thing.

[Chevelle454]

Both trucks are coil spring suspension, no leafs except for the single leaf overload on the C20 rear. Not sure which 4 speed for sure, but I wanna say saginaw....

[Longhorn Man]

a c/20 frame is in fact thicker, and has added braces.
A 5th wheel mount in a 1/2 ton is asking for trouble in all reality.

[Chevelle454]

So my best bet then is to transfer the body/engine/transmission over to the C20 and make sure the brakes and suspension are in great shape? Anyone have the tow rating of a C20 with a 350 with a 4 speed?

[69Beauty]

Unlimited!

[dubds10]

Originally Posted by Chevelle454

Well, first of all...it's been a long time since I've been here but I'm picking up my old projects again and it's good to be back!

So here's my dilemma...

I recently purchased a 24' 6500lb fifth wheel camper trailer. I was told that my 2002 F150 4x4 5.4L would pull it, but it would be pretty borderline.... Of course I didn't have a fifth wheel hitch in the truck already to test it out first, but the trailer was a good deal so I went through with it and purchased it. I bought and installed the hitch in the Ford, only to discover that it has a hell of a time just getting to 55 mph. I can hit 65 or 70, but you have to floor it the whole way there and then stay about 3/4 throttle to maintain speed on a flat grade. Wind seems to be the biggest factor, as the trailer sits about twice as high as the truck. Obviously, this is not going to work...

I can see your main dilemma a mile away The wind resistance is what will get you into trouble with anything. The weight isn't so much an issue. The C10 and C20 would both pull 6500lbs easy enough. It may pull the trailer a little better than the Ford but you wont know till you try it. But a nice diesel in the C20 might help

[yob2kanobe]

Trade in the F150 for a superduty. Leave the vintage iron as is.

[treveiger]

c20s have thicker frames. Of course youll get more power with a diesel but thats not very cost effective either and takes some time to switch it over. Youd be better off trading in the ford for a Dmax. With the sm465 and the right gearing you can pull a house down but you wont get great highway speeds and youll go through gas. My truck is a 307/sm465 combo with either a 4.10 or a 4.56 rear end and i can run that thing down the interstate pretty good but i never hauled anything with it as we have a Dmax for that now. Your best bet would be switch everything over to the c20 so you have the stronger set up but if im not mistaken youd have to weld new cab supports on as the c10s and c20s are different. Either way theres some work up ahead for you.

[Chevelle454]

A Duramax would be nice, but again out of my price range. A diesel in the C20 was in the back of my mind as well, I've seen many 12 valve cummins swaps but I don't want to deal with mounting an intercooler somewhere and converting over to diesel. Plus it doesn't sound right going down the road in a Chevy

I'm making a price list now of everything I would need for the C20 to make it a good hauler, including removing the coils and having airbags all the way around...

[treveiger]

^^^ya i figure if i ever put a diesel in a chevy itd be a Dmax.

My c20 has coil springs with the overload leafs which are nice.

[eagleuh1]

My 68 C20 has a 2005 5.3 with 4l60e, D60 with 4.56:1 gearing, leaf spring rear and power drum brakes all around.Power steering . Tows great with a frame hitch pulling 5,000 lb trailer and 800 lb motorcycle in bed. Brakes I redid first. Front suspensions being rebuilt now. Pulled from Arkansas to Arizona and back, Louisianna and back, no problems. Also have additional tranny cooler installed. Largest I found at Advanced Auto parts. Has 4 core heavy duty OE style radiator also. Hit plenty of mountains and hills, no problems. Also 20 mph head and side winds. Averaged 10-12 mpg towing.