Replacing Both Fuel Tanks on 1986 C10 Long Bed — Need Advice

[jmanjeeper]

Hi everyone,

I’m planning to replace both 16 gallon fuel tanks on my 1986 C10 long bed with 20-gallon tanks. The truck has a 383 engine. I’m trying to buy everything I need now while the Labor Day sales are running. Just have a few questions and would appreciate any advice:

• Is it possible to run 20-gallon tanks on both sides without major modifications?
• Will I need to modify fuel lines, mounting brackets, or the fuel selector valve?
• Should I look for tanks from ’87 and newer since I’ve heard those are baffled?
• Or would it be better to get ’86 tanks designed for EFI, as they might already have baffles?

Thanks in advance for your help!

— J

 

[Keith Seymore]

yes, yes, yes, and 1987 was the first year for TBI in full size trucks so no baffles in 1986 model year tanks.

K

 

[jmanjeeper]

What is the benefit of baffles? I am not running TBI, but a lil research is telling me baffles may be best for sloshing fuel in the tanks.

The truck is going under the knife for a rest-o-mod...figured it was a good time to replace the tanks since the passenger side has had holes in it since I got the truck a decade ago.

If too much has to be modified, I may just stick with the 16-gallon tanks. How much needs to be modified? If the truck came with a 20 gallon if running a single tank, I would ASSUME it's the same frame and mounting locations. But I also knwo what assuming does.

 

[Ricko1966]

Buy 2 20 gallon tanks tank straps,2 vent hoses for 20 gallon tanks. And that's about it. Seems I had to reuse a section of my original vent hose,and couple it to my new vent hose. But an easy swap. I did it by accident,it was that easy. I had 16 gallon tanks got 20 gallon tanks not realizing I had 16 gallon tanks,still didn't realize it until I had the 20 up in place and had to rework my vent hoses.

 

[Nasty-LSX]

What was the outcome? Get 2 (tanks ink) tanks for FI. The best out there for the price.