Lack of power

[Charlief]

I'm new here so bear with me. I have a 1977 C20 Camper Special 454/400 3.21 rear. it has 2K over 100K on it. We have a 28' camper we tow with it. On flat ground it pulls no problem but going up hills it lacks power . At the bottom of the hill I could be doing 65 but at the top maybe 35. I know this engine is no power house but I'd think it would pull better. If I change to an RV cam would that be enough? Any other thoughts Thanks.

 

[Snoots]

I'd look at the timing advance before I'd throw money at it.

 

[idahovette]

If it really has 3.21 gears in it, the first thing I would look at doing would probably be a lower gear??

 

[Charlief]

according to the build sheet it is a 3.21 I was thinking of a 4/11 or 4/10

 

[GXPWeasel]

Wow, you definitely need to change something. I pull a 29 foot camper with my half ton (2015 Silverado) and I have no problem pulling the damn thing 80mph if I want. I just don't have the suspension for me to want to pull farther than about 2 hours drive from home. And let me be clear, I don't pull that fast. I just have gotten up to that speed before when I wasn't paying attention. Usually keep her around 65 for safety sake.

I agree an old 454 probably has the same wheel hp as a modern 5.3, so you shouldn't be having those issues. Check your actual gearing, and if it really is that high, I'd change to something lower for sure.

 

[Bextreme04]

New from the factory in 77, that 454 only had 245hp and 365ft-lb of torque. Those 3.21's were the standard gear ratio for a 454 C20 in that year. A good RV cam, free flowing exhaust, and better gearing would make a world of difference. Biggest benefit would probably be the gearing though. Should be very easy to find a 4.10 geared 14 bolt FF floating around for $300 or less.

You can find the factory vehicle info kit on your year truck here:
https://www.gmheritagecenter.com/do...its/Chevrolet-Trucks/1977-Chevrolet-Truck.pdf

Wow, you definitely need to change something. I pull a 29 foot camper with my half ton (2015 Silverado) and I have no problem pulling the damn thing 80mph if I want. I just don't have the suspension for me to want to pull farther than about 2 hours drive from home. And let me be clear, I don't pull that fast. I just have gotten up to that speed before when I wasn't paying attention. Usually keep her around 65 for safety sake.

I agree an old 454 probably has the same wheel hp as a modern 5.3, so you shouldn't be having those issues. Check your actual gearing, and if it really is that high, I'd change to something lower for sure.

A 2015 Silverado not only has better gearing, it also makes WAY more power and has a 6-speed trans that keeps the engine right in the best powerband. Factory rated power on the 2015 5.3 is 355hp and 383lb-ft, and it isn't 50 years old. Our 2011 Suburban slows down quite a bit going up hills when towing and it has 3.21's. I'll be changing the gears out for 4.10's soon and am expecting it to help quite a bit.

 

[potent rodent]

first thing i would do is check fuel filter, make sure timing is set, could be a little of both