1985 f150 throttle body

[jgraham368]

seems that the current throttle body is on its way out curious if there is any advantage to a bigger on or if it is best to keep it stock size

[Gary Lewis]

Welcome to the Bullnose Forum!  

I think you may have missed the part of my email that asked you to go to the New Members Start Here folder and read the guidelines.  Part of the guidelines say:

As said, we do help each other with our trucks, and it is always wise to know the specifics about a vehicle before giving advice.  Toward that end we request that all users either state in the thread all the pertinent details about their truck or, preferably, put that info in their signature so those trying to help you do not have to go searching for the info.

But you didn't state anything about your truck, nor put the information in a signature, which is another option.  So we can only assume that you have an '85 302 with EFI, but it is possible that you have a different engine with EFI.  And, your gear ratio and use of the truck makes a big difference.  Could you help us understand what you have and how you use it?

[jgraham368]

oops yes i do apologize. yes it is the 302 efi. stock gear ratio. not sure just picked the truck up two days ago. and am just making it 100% road worthy or at least to the best of my ability. noting has been done to the truck will be using it for a daily driver light towing.

[Gary Lewis]

You can decode the certification label, that should be on the driver's door post, here: Specifications/Certification Label.  And from that you should be able to determine the gear ratio.

But, there isn't a "stock" gear ratio as these trucks came with a range of ratios.  And you still didn't say if it is an '85 or '86, nor if auto or manual, and that makes a difference in what gears Ford might have put in it.

If you look at the Towing information you can see that an '85 with a manual tranny would have come with a ratio from 3.00 to 3.73, while an '85 w/an auto tranny would have a range from 3.50 to 4.11.

But back to the original question: For daily driving and light trailer towing I would stay with the stock throttle body size.

[85lebaront2]

The only actual larger factory throttle body is the one for the 7.5L engine. It will physically fit, but, 7.5L engines have the idle air control on the plenum, the throttle cable connections are different (could be a mjor issue with an AOD), there are no water passages to prevent icing, there are no canister purge ports and due to the larger size you will need a different air inlet system.

FWIW, 5.0L and 5.8L use the same throttle body, if you want to change, look for a "self cleaning" one, they are teflon coated inside.