Wanting a 73-87 Dually. have questions

[Mild Thunder]

Hi guys and gals. I am in the market for a 73-87 C30, or k30 Dually. Always liked the look of them. Basically the trucks job would be to tow my old cigarette boat to and from the marina about 5 miles away, and maybe a couple longer distance tows. The boat and trailer weigh around 14k lbs (40ft boat).

Is there any years that were better than others? Prefer the 454/TH400, but open to a 4spd. Looking for the years with the best braking system, HD suspension, etc. Also, must be a crew cab. What gear ratios came stock with these trucks? 3.73? 4.10? etc. Also curious to whether the 4spd would pull the heavy load better with the steeper first gear? Thanks for any input!

FYI, i tow the boat now with a 2004 F250 superduty powerstroke. Powerwise it pulls great, but its just too much boat for a single rear wheel truck. Thinking the dually should be much more stable goin down the road.

[fitz]

I would say go with an 87-91 with the TBI 454.
I've owned 2, an 88 4x4 and a 91 2wd. Both had the TBI 454 in them with 4.10's.
I never used them for towing so can't help you there but I've noticed most of the newer trucks are rated to tow more when equipped with the auto trans.

[Mild Thunder]

I would say go with an 87-91 with the TBI 454.
I've owned 2, an 88 4x4 and a 91 2wd. Both had the TBI 454 in them with 4.10's.
I never used them for towing so can't help you there but I've noticed most of the newer trucks are rated to tow more when equipped with the auto trans.

Are the TBI trucks more powerrful than the carb versions? What years were the best for HP/Torque in the 454's?

[Captkaos]

For power they are pretty much the same.  TBI adds driveability/reliability and better startup.
I would try to find a 91 with the 454/4L80E.

[Whitfield]

My 88 is a V-3500.   

I believe the C /K's are standard cab.

88-91 454 auto.   

Hmmm  I didn't know the 4l80e was offered in 91.    Nice!!!

[Blazin]

C = 2 wheel drive untill 86
K = 4 wheel drive untill 86
R = 2 wheel drive from 87 untill end of production
V = 4 wheel drive from 87 untill end of production
Crew or single cab makes no difference.

[DnStClr]

That's a lot of boat/trailer for a one ton truck to tow. By the time you add the weight of the truck and cargo, including people, I think you're going to be well over the tow limits of the dually. I betcha you're looking at 21,000 lbs or better. That's got to be medium duty territory. 

[Mild Thunder]

That's a lot of boat/trailer for a one ton truck to tow. By the time you add the weight of the truck and cargo, including people, I think you're going to be well over the tow limits of the dually. I betcha you're looking at 21,000 lbs or better. That's got to be medium duty territory. 

Plans have changed. New boat coming. Will weigh around 11k lbs including the trailer. These cigarette boats might be heavy, but they tow much better than any tag along camper or similiar trailer. They are long, triple axle trailers, low profile, and usually have big brakes on all three axles.

How were the TBI trucks on fuel compared to the carbed trucks??

[Captkaos]

My 91 CC with a TBI 350 that probably needs a tune up, gets 14 city/17mpg on the highway.  Most of the carb'd ones are going to be around 12 from past experience.

[Mild Thunder]

Found a nice K30 Dually. Downside is it has a carbed 350 in it. How hard would it be to swap a 454 into it??? Mounts, etc?

[Captkaos]

Unbolt the SBC, bolt the BBC in.  Exhaust hooks up different, need a bigger radiator, there is probably more I am forgetting but you can search the forum this is covered ALOT.

[PRattenbury]

If I had to tow that heavy I'd go diesel FTW.

[fitz]

If I had to tow that heavy I'd go diesel FTW.

I would take the big block over the 6.2 for towing.

[PRattenbury]

I'd take an air-cooled Volkswagen over a 6.2. But a Duramax is a good diesel. Cummins is aweome. Detroits...

[fitz]

I'd take an air-cooled Volkswagen over a 6.2. But a Duramax is a good diesel. Cummins is aweome. Detroits...

I've yet to see a VW, Duramax, or Cummings come from the factory in a 73-87.