tow vehicle

Charles F Fisher wrote:
We have a 1987 Coachman 5th wheel. We pull it with a 77 C20 Chevy Camper Special It has a 454 from the factory the rear is a 3.21 ratio our problem is long steep hills. We hit the bottom doing 65 and by the top we are at maybe 30. Do I change the rear to 4/11 or build up the engine. The truck is like new been in storage a long time with no rust and the camper is in the same condition.

You could do both, but changing gear ratios would likely help a lot. If you are down to 30 mph it sounds like you are in first gear at the top of the hill. Lower gears might allow you to pull the hill in second to give you another 10-15 mph. But like was pointed out, you only have around 200 hp or so. If you change the gear ratio to 4.11 a GearVendors unit would give you about the same final drive ratio in overdrive as what you have now. It's a little spendy and like was mentioned previously doesn't work in 4WD.

And if you take what you’d easily spend to add some power, some gearing and a GV to it and combine that with what the OP is saying is a very valuable truck as is, you could step up even more than just the value of the truck alone.

OP said it was a C20...two wheel drive. K20 was the Chevy designation for 3/4 ton 4x4.

Seon wrote:
Would an "Over and Under" gear box work?

https://www.gearvendors.com/index.html

That is my plan for the Sub in signature. The 4 speed becomes an 8 speed and if the diff’s are changed to something like 4.1’s or even higher numeric, it will still have a good OD

And let’s see some pics of this truck! I’m excited !

Charles F Fisher wrote:
We have a 1987 Coachman 5th wheel. We pull it with a 77 C20 Chevy Camper Special It has a 454 from the factory the rear is a 3.21 ratio our problem is long steep hills. We hit the bottom doing 65 and by the top we are at maybe 30. Do I change the rear to 4/11 or build up the engine. The truck is like new been in storage a long time with no rust and the camper is in the same condition.

If the truck actually what you say it is.... “Like new” is generally a way over used term...
Then your best bang for the buck is to sell it, as a like new truck like that will fetch $15k or more. Then use that money to buy something that will tow, drive and ride far better.

jdc1 wrote:
Drop a cam and a 750 carb in it. Double your horsepower. You'll love it after that.

A cam and carb add 200+ hp? That’s a great idea....wonder why more people don’t do that?
Lol

KD4UPL wrote:
That is a really cool truck. I love that body style. I assume you have a TH400 transmission and thus no overdrive. I don't know that I would go all the way to a 4:10 gear. A 3.73 would make a noticeable difference. Is the truck 4wd? If so you need to change both the front and rear gearing. It will cost you about $1,000 for each axle.
The gearvendors unit would also work but you couldn't use it in 4wd; that may or may not be an issue for you.
Does that engine even have a 4 barrel carburateur? If not, I would change the carb. Otherwise, short of a complete rebuilt, I would leave the engine alone. But, a full rebuild on that engine would be really cool. You could get nearly double the HP out of it with not much trouble.

Yes it has a 4bbl, no it isn’t 4wd and no it doesn’t have overdrive.
And a gear vendors would be useless. He needs more rpms not more speed.

what cam? been thinking of that

Drop a cam and a 750 carb in it. Double your horsepower. You'll love it after that.