300 I6 MPG
Moderator
Joined: Dec 2007
Posts: 7,987
Likes: 104
From: Boise, Idaho
Hi Folks, I've been battling with this same issue. I have a 1981 Class C RV built on an F250 chassis. It's about 20 ft and weighs about 6500#. It has a 300 with a 1 barrel carb and C6 trans with around 50k (150k ?). I have been stockpiling parts for awhile. So far I have a Offy C, New 2 barrel carb, ZF 5-342, pedal assembly (with clutch), EFI manifolds and Walker Y.
I also have a Cummins 5.9 I pulled from a school bus with only 46k, and a bread truck SBF to Cummins adapter and flywheel that will work with the same trans. Would need to fab motor mounts and exhaust out of the stuff I pulled from the bus.
I think I've decided to install the 300 hop ups and ZF, and see how that works, since thats the easiest route. Mileage and being able to keep up with traffic are my main considerations.
I also have a Cummins 5.9 I pulled from a school bus with only 46k, and a bread truck SBF to Cummins adapter and flywheel that will work with the same trans. Would need to fab motor mounts and exhaust out of the stuff I pulled from the bus.
I think I've decided to install the 300 hop ups and ZF, and see how that works, since thats the easiest route. Mileage and being able to keep up with traffic are my main considerations.
Honestly, the stock exhaust and carb/intake are the reason the 300 is so sluggish. Once those are replaced with something that allows the engine to breath better, it's slouch status is revoked and it'll move how you want it to.
Replacing the C6 with a ZF5 is going to probably be your biggest mpg increase.
Thread
Thread Starter
Forum
Replies
Last Post
arctic y block
General Automotive Discussion
8
Nov 8, 2014 07:55 PM
Tgure
Ford Inline Six, 200, 250, 4.9L / 300
3
Apr 26, 2011 12:08 PM
rdw516
1987 - 1996 F150 & Larger F-Series Trucks
14
Dec 7, 2009 03:32 PM
