Older Chevy truck 454

[screwballl]

Has anyone here tried a HHO setup on older Chevy trucks/cars with the larger engines (350 and larger)? If so what kind of gains were seen?
I have a 91 Suburban 3/4 ton with a 454 TBI that typically sees 10 mpg around town, was wondering what kind out output and setup would work best with a large motor like this. Since it doesn't have all the extra sensors I would assume the gains would be better than newer computer based vehicles.

[Calgary]

Hi . I am installing a HHO unit in my 23' motorhome in May or June next year. It is a 1991 TBI 454 just like yours. I am getting 10 mpg.(imperial gallon). Your set up should be the same as mine. I have 1 oxygen sensor on the Y pipe. You will need an efie hooked up to the oxygen sensor. I left the single exhaust intact because a performance shop told me I wouldn't gain that much mileage with the 3" exhaust already on it. That's how I am hooking my unit up. The only thing I am not sure of yet is how many Litres per min. I will need. I will hook up 2 units if 1 doesn't do the trick. The one I ordered is claimed to make 1.5 to 2 litres per min. I am installing that one on my 2001 toyota corrolla. My motorhome is in storage for the winter so it will have to wait. This way I get to experiment with my daily driver first and work out any kinks in the system. Hope this helps. Jim

[screwballl]

Thanks for the info.
As for sensors, mine had the cat removed at some point and do not see an O2 sensor so hopefully that will not be a problem for me.

I have a 1991 Chevy Suburban R2500 with 7.4L 454 and the single 3" pipe.

I have been reading here to find out what works better for large engines but most everyone is either testing on large diesels or small block V8s and smaller.